DrTVRao MD

DISINFECTION IN HOSPITALS

DRTVRAO MD 1

WHAT IS DISINFECTION

bull Disinfection may be defined as Cleaning an

article of some or all of the pathogenic

organisms which may cause infection

bull Perfect disinfectant would also offer complete

and full sterilization without harming other forms

of life be inexpensive and non-corrosive

Unfortunately ideal disinfectants do not exist

Most disinfectants are also by their very nature

potentially harmful (even toxic) to humans or

animals DRTVRAO MD 2

THE IDEAL DISINFECTANT

Resistant to inactivation

Broadly active (killing pathogens)

Not poisonous (or otherwise harmful)

Penetrating (to pathogens)

Not damaging to non-living materials

Stable

Easy to work with

Otherwise not unpleasant DRTVRAO MD 3

WHY DISINFECTION AND STERILIZATION

bull Contagious diseases

bull Hospital infection (eg OR ID ward) or other opportunistic infection

bull Lab contamination

bull Etc

bull Microbes

- usually easy to grow in environment

- but also can be inhibited or killed by certain environmental (physical or

chemical) factorsconditions

DRTVRAO MD 4

TERMINOLOGY

bull Antisepsis chemical destruction of vegetative pathogens on living tissue

bull Degerming mechanical removal of microbes from limited area

bull Sanitization lowering microbial counts on eating and drinking utensils to safe levels

DRTVRAO MD 5

TERMINOLOGY

bull Biocide or germicide kills microorganisms

bull Fungicide kills fungi

bull Virocide inactivates viruses

bull Bacteriostatic agent stops growth of bacteria

DRTVRAO MD 6

ANTISEPTICS VERSUS DISINFECTANTS

Antiseptics Use on skin and mucous membranes to kill microorganisms

Not for use on inanimate objects

Disinfectants

Use to kill microorganisms on inanimate objects

Not for use on skin or mucous membranes

High-level versus low-level disinfectants

DRTVRAO MD 7

BEGINNING OF SCIENTIFIC ERA OF

STERILIZATION AND DISINFECTION

DRTVRAO MD 8

bull Process of reducing or

eliminating living

pathogenic

microorganisms in or

on materials so they

are no longer a health

hazard

For example use of alcohol before drug injection

DISINFECTION

DRTVRAO MD 9

bull Process of destroying all microbial forms A sterile object is one free of all microbial forms including bacterial spores

bull More thorough than disinfection

STERILIZATION

DRTVRAO MD 10

Soaps are sodium or

potassium salts of fatty

acids a natural product

Detergents instead are

artificial surfactants

While soaps are always

negatively charged some

detergents are negatively

charged while others are

positively charged

One example of a

positively charged

detergent are quaternary

ammonium compounds

(aka quats)

SOAP AND DETERGENTS

DRTVRAO MD 11

HALOGENS

Halogens are the seventh (VII) column of the periodic table of elements

Two halogens are regularly employed as antimicrobials Iodine and

Chloride

Iodine commonly used as an antiseptic against all microbes fungi and

viruses

Iodine It inhibits protein synthesis and oxidizes ndashSH groups of amino

acids

Chlorine Used as a disinfectant (10 bleach)

Chlorine Hypochlorous acid (HOCl) is a product formed in water that is

the active form of the disinfectant

Chlorine Applied in treatment of drinking water swimming pool and

sewage

DRTVRAO MD 12

ANTIMICROBIAL MODES OF ACTION OF

DISINFECTANTS AND ANTISEPTICS

bull Denaturation of bacterial proteins by disrupting hydrogen and disulfide bonds

mdashmdash phenol (high conc) alcohol heavy-metal (high conc) acids alkalis aldehydes)

bull Damage to bacterial membrane (lipids andor proteins) causing leakage of intracellular molecules

mdashmdash phenol (low conc) surfactants dyes

bull Interference of bacterial enzyme and metabolism

mdashmdash oxidants heavy-metals (low conc) alkylating agents

DRTVRAO MD 13

bull Alkylating agent（烷化剂）

mdashmdash alkylating

proteins and nucleic

acids bull formalin (formaldehyde) mdashmdash

surface disinfection air

surgical instruments

bull glutaric dialdehydemdash high-

precision instruments

endoscopes

bull 50mgL epoxy ethane mdashmdash

surgical instruments and

dressing

ALKYLATING PROTEINS AND NUCLEIC ACIDS

DRTVRAO MD 14

bull Phenol and phenol derivatives

mdashmdash altering membrane permeability and denaturing proteins

bull 001 - 005 Chlorhexidine）mdashmdash vaginal wash OR hand-wash

bull 3 - 5 carbonic acid or 2 Lysol mdashmdash floor or surface disinfection

PHENOL AND PHENOL DERIVATIVES

DRTVRAO MD 15

bull Alcohols mdashmdash denaturing bacterial proteins and

membranes

bull 70 - 75 ethyl or isopropyl alcoholmdashmdash skin and thermometer disinfection

ndash ineffective against endospores and non-enveloped viruses

ALCOHOLS

DRTVRAO MD 16

bull Oxidants

mdashmdash oxidation protein precipitation

bull 3 peroxidemdashmdash small trauma wound skin mucosa

bull 02 - 1 peroxyacetic acidmdashmdash plastics glassware

bull 02 ndash 05 ppm chlorines mdashmdash water and swimming pool

bull 01 potassium permanganatemdashmdash skin

fruitsvegetables

DRTVRAO MD 17

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

WHAT IS DISINFECTION

bull Disinfection may be defined as Cleaning an

article of some or all of the pathogenic

organisms which may cause infection

bull Perfect disinfectant would also offer complete

and full sterilization without harming other forms

of life be inexpensive and non-corrosive

Unfortunately ideal disinfectants do not exist

Most disinfectants are also by their very nature

potentially harmful (even toxic) to humans or

animals DRTVRAO MD 2

THE IDEAL DISINFECTANT

Resistant to inactivation

Broadly active (killing pathogens)

Not poisonous (or otherwise harmful)

Penetrating (to pathogens)

Not damaging to non-living materials

Stable

Easy to work with

Otherwise not unpleasant DRTVRAO MD 3

WHY DISINFECTION AND STERILIZATION

bull Contagious diseases

bull Hospital infection (eg OR ID ward) or other opportunistic infection

bull Lab contamination

bull Etc

bull Microbes

- usually easy to grow in environment

- but also can be inhibited or killed by certain environmental (physical or

chemical) factorsconditions

DRTVRAO MD 4

TERMINOLOGY

bull Antisepsis chemical destruction of vegetative pathogens on living tissue

bull Degerming mechanical removal of microbes from limited area

bull Sanitization lowering microbial counts on eating and drinking utensils to safe levels

DRTVRAO MD 5

TERMINOLOGY

bull Biocide or germicide kills microorganisms

bull Fungicide kills fungi

bull Virocide inactivates viruses

bull Bacteriostatic agent stops growth of bacteria

DRTVRAO MD 6

ANTISEPTICS VERSUS DISINFECTANTS

Antiseptics Use on skin and mucous membranes to kill microorganisms

Not for use on inanimate objects

Disinfectants

Use to kill microorganisms on inanimate objects

Not for use on skin or mucous membranes

High-level versus low-level disinfectants

DRTVRAO MD 7

BEGINNING OF SCIENTIFIC ERA OF

STERILIZATION AND DISINFECTION

DRTVRAO MD 8

bull Process of reducing or

eliminating living

pathogenic

microorganisms in or

on materials so they

are no longer a health

hazard

For example use of alcohol before drug injection

DISINFECTION

DRTVRAO MD 9

bull Process of destroying all microbial forms A sterile object is one free of all microbial forms including bacterial spores

bull More thorough than disinfection

STERILIZATION

DRTVRAO MD 10

Soaps are sodium or

potassium salts of fatty

acids a natural product

Detergents instead are

artificial surfactants

While soaps are always

negatively charged some

detergents are negatively

charged while others are

positively charged

One example of a

positively charged

detergent are quaternary

ammonium compounds

(aka quats)

SOAP AND DETERGENTS

DRTVRAO MD 11

HALOGENS

Halogens are the seventh (VII) column of the periodic table of elements

Two halogens are regularly employed as antimicrobials Iodine and

Chloride

Iodine commonly used as an antiseptic against all microbes fungi and

viruses

Iodine It inhibits protein synthesis and oxidizes ndashSH groups of amino

acids

Chlorine Used as a disinfectant (10 bleach)

Chlorine Hypochlorous acid (HOCl) is a product formed in water that is

the active form of the disinfectant

Chlorine Applied in treatment of drinking water swimming pool and

sewage

DRTVRAO MD 12

ANTIMICROBIAL MODES OF ACTION OF

DISINFECTANTS AND ANTISEPTICS

bull Denaturation of bacterial proteins by disrupting hydrogen and disulfide bonds

mdashmdash phenol (high conc) alcohol heavy-metal (high conc) acids alkalis aldehydes)

bull Damage to bacterial membrane (lipids andor proteins) causing leakage of intracellular molecules

mdashmdash phenol (low conc) surfactants dyes

bull Interference of bacterial enzyme and metabolism

mdashmdash oxidants heavy-metals (low conc) alkylating agents

DRTVRAO MD 13

bull Alkylating agent（烷化剂）

mdashmdash alkylating

proteins and nucleic

acids bull formalin (formaldehyde) mdashmdash

surface disinfection air

surgical instruments

bull glutaric dialdehydemdash high-

precision instruments

endoscopes

bull 50mgL epoxy ethane mdashmdash

surgical instruments and

dressing

ALKYLATING PROTEINS AND NUCLEIC ACIDS

DRTVRAO MD 14

bull Phenol and phenol derivatives

mdashmdash altering membrane permeability and denaturing proteins

bull 001 - 005 Chlorhexidine）mdashmdash vaginal wash OR hand-wash

bull 3 - 5 carbonic acid or 2 Lysol mdashmdash floor or surface disinfection

PHENOL AND PHENOL DERIVATIVES

DRTVRAO MD 15

bull Alcohols mdashmdash denaturing bacterial proteins and

membranes

bull 70 - 75 ethyl or isopropyl alcoholmdashmdash skin and thermometer disinfection

ndash ineffective against endospores and non-enveloped viruses

ALCOHOLS

DRTVRAO MD 16

bull Oxidants

mdashmdash oxidation protein precipitation

bull 3 peroxidemdashmdash small trauma wound skin mucosa

bull 02 - 1 peroxyacetic acidmdashmdash plastics glassware

bull 02 ndash 05 ppm chlorines mdashmdash water and swimming pool

bull 01 potassium permanganatemdashmdash skin

fruitsvegetables

DRTVRAO MD 17

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

THE IDEAL DISINFECTANT

Resistant to inactivation

Broadly active (killing pathogens)

Not poisonous (or otherwise harmful)

Penetrating (to pathogens)

Not damaging to non-living materials

Stable

Easy to work with

Otherwise not unpleasant DRTVRAO MD 3

WHY DISINFECTION AND STERILIZATION

bull Contagious diseases

bull Hospital infection (eg OR ID ward) or other opportunistic infection

bull Lab contamination

bull Etc

bull Microbes

- usually easy to grow in environment

- but also can be inhibited or killed by certain environmental (physical or

chemical) factorsconditions

DRTVRAO MD 4

TERMINOLOGY

bull Antisepsis chemical destruction of vegetative pathogens on living tissue

bull Degerming mechanical removal of microbes from limited area

bull Sanitization lowering microbial counts on eating and drinking utensils to safe levels

DRTVRAO MD 5

TERMINOLOGY

bull Biocide or germicide kills microorganisms

bull Fungicide kills fungi

bull Virocide inactivates viruses

bull Bacteriostatic agent stops growth of bacteria

DRTVRAO MD 6

ANTISEPTICS VERSUS DISINFECTANTS

Antiseptics Use on skin and mucous membranes to kill microorganisms

Not for use on inanimate objects

Disinfectants

Use to kill microorganisms on inanimate objects

Not for use on skin or mucous membranes

High-level versus low-level disinfectants

DRTVRAO MD 7

BEGINNING OF SCIENTIFIC ERA OF

STERILIZATION AND DISINFECTION

DRTVRAO MD 8

bull Process of reducing or

eliminating living

pathogenic

microorganisms in or

on materials so they

are no longer a health

hazard

For example use of alcohol before drug injection

DISINFECTION

DRTVRAO MD 9

bull Process of destroying all microbial forms A sterile object is one free of all microbial forms including bacterial spores

bull More thorough than disinfection

STERILIZATION

DRTVRAO MD 10

Soaps are sodium or

potassium salts of fatty

acids a natural product

Detergents instead are

artificial surfactants

While soaps are always

negatively charged some

detergents are negatively

charged while others are

positively charged

One example of a

positively charged

detergent are quaternary

ammonium compounds

(aka quats)

SOAP AND DETERGENTS

DRTVRAO MD 11

HALOGENS

Halogens are the seventh (VII) column of the periodic table of elements

Two halogens are regularly employed as antimicrobials Iodine and

Chloride

Iodine commonly used as an antiseptic against all microbes fungi and

viruses

Iodine It inhibits protein synthesis and oxidizes ndashSH groups of amino

acids

Chlorine Used as a disinfectant (10 bleach)

Chlorine Hypochlorous acid (HOCl) is a product formed in water that is

the active form of the disinfectant

Chlorine Applied in treatment of drinking water swimming pool and

sewage

DRTVRAO MD 12

ANTIMICROBIAL MODES OF ACTION OF

DISINFECTANTS AND ANTISEPTICS

bull Denaturation of bacterial proteins by disrupting hydrogen and disulfide bonds

mdashmdash phenol (high conc) alcohol heavy-metal (high conc) acids alkalis aldehydes)

bull Damage to bacterial membrane (lipids andor proteins) causing leakage of intracellular molecules

mdashmdash phenol (low conc) surfactants dyes

bull Interference of bacterial enzyme and metabolism

mdashmdash oxidants heavy-metals (low conc) alkylating agents

DRTVRAO MD 13

bull Alkylating agent（烷化剂）

mdashmdash alkylating

proteins and nucleic

acids bull formalin (formaldehyde) mdashmdash

surface disinfection air

surgical instruments

bull glutaric dialdehydemdash high-

precision instruments

endoscopes

bull 50mgL epoxy ethane mdashmdash

surgical instruments and

dressing

ALKYLATING PROTEINS AND NUCLEIC ACIDS

DRTVRAO MD 14

bull Phenol and phenol derivatives

mdashmdash altering membrane permeability and denaturing proteins

bull 001 - 005 Chlorhexidine）mdashmdash vaginal wash OR hand-wash

bull 3 - 5 carbonic acid or 2 Lysol mdashmdash floor or surface disinfection

PHENOL AND PHENOL DERIVATIVES

DRTVRAO MD 15

bull Alcohols mdashmdash denaturing bacterial proteins and

membranes

bull 70 - 75 ethyl or isopropyl alcoholmdashmdash skin and thermometer disinfection

ndash ineffective against endospores and non-enveloped viruses

ALCOHOLS

DRTVRAO MD 16

bull Oxidants

mdashmdash oxidation protein precipitation

bull 3 peroxidemdashmdash small trauma wound skin mucosa

bull 02 - 1 peroxyacetic acidmdashmdash plastics glassware

bull 02 ndash 05 ppm chlorines mdashmdash water and swimming pool

bull 01 potassium permanganatemdashmdash skin

fruitsvegetables

DRTVRAO MD 17

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

WHY DISINFECTION AND STERILIZATION

bull Contagious diseases

bull Hospital infection (eg OR ID ward) or other opportunistic infection

bull Lab contamination

bull Etc

bull Microbes

- usually easy to grow in environment

- but also can be inhibited or killed by certain environmental (physical or

chemical) factorsconditions

DRTVRAO MD 4

TERMINOLOGY

bull Antisepsis chemical destruction of vegetative pathogens on living tissue

bull Degerming mechanical removal of microbes from limited area

bull Sanitization lowering microbial counts on eating and drinking utensils to safe levels

DRTVRAO MD 5

TERMINOLOGY

bull Biocide or germicide kills microorganisms

bull Fungicide kills fungi

bull Virocide inactivates viruses

bull Bacteriostatic agent stops growth of bacteria

DRTVRAO MD 6

ANTISEPTICS VERSUS DISINFECTANTS

Antiseptics Use on skin and mucous membranes to kill microorganisms

Not for use on inanimate objects

Disinfectants

Use to kill microorganisms on inanimate objects

Not for use on skin or mucous membranes

High-level versus low-level disinfectants

DRTVRAO MD 7

BEGINNING OF SCIENTIFIC ERA OF

STERILIZATION AND DISINFECTION

DRTVRAO MD 8

bull Process of reducing or

eliminating living

pathogenic

microorganisms in or

on materials so they

are no longer a health

hazard

For example use of alcohol before drug injection

DISINFECTION

DRTVRAO MD 9

bull Process of destroying all microbial forms A sterile object is one free of all microbial forms including bacterial spores

bull More thorough than disinfection

STERILIZATION

DRTVRAO MD 10

Soaps are sodium or

potassium salts of fatty

acids a natural product

Detergents instead are

artificial surfactants

While soaps are always

negatively charged some

detergents are negatively

charged while others are

positively charged

One example of a

positively charged

detergent are quaternary

ammonium compounds

(aka quats)

SOAP AND DETERGENTS

DRTVRAO MD 11

HALOGENS

Halogens are the seventh (VII) column of the periodic table of elements

Two halogens are regularly employed as antimicrobials Iodine and

Chloride

Iodine commonly used as an antiseptic against all microbes fungi and

viruses

Iodine It inhibits protein synthesis and oxidizes ndashSH groups of amino

acids

Chlorine Used as a disinfectant (10 bleach)

Chlorine Hypochlorous acid (HOCl) is a product formed in water that is

the active form of the disinfectant

Chlorine Applied in treatment of drinking water swimming pool and

sewage

DRTVRAO MD 12

ANTIMICROBIAL MODES OF ACTION OF

DISINFECTANTS AND ANTISEPTICS

bull Denaturation of bacterial proteins by disrupting hydrogen and disulfide bonds

mdashmdash phenol (high conc) alcohol heavy-metal (high conc) acids alkalis aldehydes)

bull Damage to bacterial membrane (lipids andor proteins) causing leakage of intracellular molecules

mdashmdash phenol (low conc) surfactants dyes

bull Interference of bacterial enzyme and metabolism

mdashmdash oxidants heavy-metals (low conc) alkylating agents

DRTVRAO MD 13

bull Alkylating agent（烷化剂）

mdashmdash alkylating

proteins and nucleic

acids bull formalin (formaldehyde) mdashmdash

surface disinfection air

surgical instruments

bull glutaric dialdehydemdash high-

precision instruments

endoscopes

bull 50mgL epoxy ethane mdashmdash

surgical instruments and

dressing

ALKYLATING PROTEINS AND NUCLEIC ACIDS

DRTVRAO MD 14

bull Phenol and phenol derivatives

mdashmdash altering membrane permeability and denaturing proteins

bull 001 - 005 Chlorhexidine）mdashmdash vaginal wash OR hand-wash

bull 3 - 5 carbonic acid or 2 Lysol mdashmdash floor or surface disinfection

PHENOL AND PHENOL DERIVATIVES

DRTVRAO MD 15

bull Alcohols mdashmdash denaturing bacterial proteins and

membranes

bull 70 - 75 ethyl or isopropyl alcoholmdashmdash skin and thermometer disinfection

ndash ineffective against endospores and non-enveloped viruses

ALCOHOLS

DRTVRAO MD 16

bull Oxidants

mdashmdash oxidation protein precipitation

bull 3 peroxidemdashmdash small trauma wound skin mucosa

bull 02 - 1 peroxyacetic acidmdashmdash plastics glassware

bull 02 ndash 05 ppm chlorines mdashmdash water and swimming pool

bull 01 potassium permanganatemdashmdash skin

fruitsvegetables

DRTVRAO MD 17

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

TERMINOLOGY

bull Antisepsis chemical destruction of vegetative pathogens on living tissue

bull Degerming mechanical removal of microbes from limited area

bull Sanitization lowering microbial counts on eating and drinking utensils to safe levels

DRTVRAO MD 5

TERMINOLOGY

bull Biocide or germicide kills microorganisms

bull Fungicide kills fungi

bull Virocide inactivates viruses

bull Bacteriostatic agent stops growth of bacteria

DRTVRAO MD 6

ANTISEPTICS VERSUS DISINFECTANTS

Antiseptics Use on skin and mucous membranes to kill microorganisms

Not for use on inanimate objects

Disinfectants

Use to kill microorganisms on inanimate objects

Not for use on skin or mucous membranes

High-level versus low-level disinfectants

DRTVRAO MD 7

BEGINNING OF SCIENTIFIC ERA OF

STERILIZATION AND DISINFECTION

DRTVRAO MD 8

bull Process of reducing or

eliminating living

pathogenic

microorganisms in or

on materials so they

are no longer a health

hazard

For example use of alcohol before drug injection

DISINFECTION

DRTVRAO MD 9

bull Process of destroying all microbial forms A sterile object is one free of all microbial forms including bacterial spores

bull More thorough than disinfection

STERILIZATION

DRTVRAO MD 10

Soaps are sodium or

potassium salts of fatty

acids a natural product

Detergents instead are

artificial surfactants

While soaps are always

negatively charged some

detergents are negatively

charged while others are

positively charged

One example of a

positively charged

detergent are quaternary

ammonium compounds

(aka quats)

SOAP AND DETERGENTS

DRTVRAO MD 11

HALOGENS

Halogens are the seventh (VII) column of the periodic table of elements

Two halogens are regularly employed as antimicrobials Iodine and

Chloride

Iodine commonly used as an antiseptic against all microbes fungi and

viruses

Iodine It inhibits protein synthesis and oxidizes ndashSH groups of amino

acids

Chlorine Used as a disinfectant (10 bleach)

Chlorine Hypochlorous acid (HOCl) is a product formed in water that is

the active form of the disinfectant

Chlorine Applied in treatment of drinking water swimming pool and

sewage

DRTVRAO MD 12

ANTIMICROBIAL MODES OF ACTION OF

DISINFECTANTS AND ANTISEPTICS

bull Denaturation of bacterial proteins by disrupting hydrogen and disulfide bonds

mdashmdash phenol (high conc) alcohol heavy-metal (high conc) acids alkalis aldehydes)

bull Damage to bacterial membrane (lipids andor proteins) causing leakage of intracellular molecules

mdashmdash phenol (low conc) surfactants dyes

bull Interference of bacterial enzyme and metabolism

mdashmdash oxidants heavy-metals (low conc) alkylating agents

DRTVRAO MD 13

bull Alkylating agent（烷化剂）

mdashmdash alkylating

proteins and nucleic

acids bull formalin (formaldehyde) mdashmdash

surface disinfection air

surgical instruments

bull glutaric dialdehydemdash high-

precision instruments

endoscopes

bull 50mgL epoxy ethane mdashmdash

surgical instruments and

dressing

ALKYLATING PROTEINS AND NUCLEIC ACIDS

DRTVRAO MD 14

bull Phenol and phenol derivatives

mdashmdash altering membrane permeability and denaturing proteins

bull 001 - 005 Chlorhexidine）mdashmdash vaginal wash OR hand-wash

bull 3 - 5 carbonic acid or 2 Lysol mdashmdash floor or surface disinfection

PHENOL AND PHENOL DERIVATIVES

DRTVRAO MD 15

bull Alcohols mdashmdash denaturing bacterial proteins and

membranes

bull 70 - 75 ethyl or isopropyl alcoholmdashmdash skin and thermometer disinfection

ndash ineffective against endospores and non-enveloped viruses

ALCOHOLS

DRTVRAO MD 16

bull Oxidants

mdashmdash oxidation protein precipitation

bull 3 peroxidemdashmdash small trauma wound skin mucosa

bull 02 - 1 peroxyacetic acidmdashmdash plastics glassware

bull 02 ndash 05 ppm chlorines mdashmdash water and swimming pool

bull 01 potassium permanganatemdashmdash skin

fruitsvegetables

DRTVRAO MD 17

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

TERMINOLOGY

bull Biocide or germicide kills microorganisms

bull Fungicide kills fungi

bull Virocide inactivates viruses

bull Bacteriostatic agent stops growth of bacteria

DRTVRAO MD 6

ANTISEPTICS VERSUS DISINFECTANTS

Antiseptics Use on skin and mucous membranes to kill microorganisms

Not for use on inanimate objects

Disinfectants

Use to kill microorganisms on inanimate objects

Not for use on skin or mucous membranes

High-level versus low-level disinfectants

DRTVRAO MD 7

BEGINNING OF SCIENTIFIC ERA OF

STERILIZATION AND DISINFECTION

DRTVRAO MD 8

bull Process of reducing or

eliminating living

pathogenic

microorganisms in or

on materials so they

are no longer a health

hazard

For example use of alcohol before drug injection

DISINFECTION

DRTVRAO MD 9

bull Process of destroying all microbial forms A sterile object is one free of all microbial forms including bacterial spores

bull More thorough than disinfection

STERILIZATION

DRTVRAO MD 10

Soaps are sodium or

potassium salts of fatty

acids a natural product

Detergents instead are

artificial surfactants

While soaps are always

negatively charged some

detergents are negatively

charged while others are

positively charged

One example of a

positively charged

detergent are quaternary

ammonium compounds

(aka quats)

SOAP AND DETERGENTS

DRTVRAO MD 11

HALOGENS

Halogens are the seventh (VII) column of the periodic table of elements

Two halogens are regularly employed as antimicrobials Iodine and

Chloride

Iodine commonly used as an antiseptic against all microbes fungi and

viruses

Iodine It inhibits protein synthesis and oxidizes ndashSH groups of amino

acids

Chlorine Used as a disinfectant (10 bleach)

Chlorine Hypochlorous acid (HOCl) is a product formed in water that is

the active form of the disinfectant

Chlorine Applied in treatment of drinking water swimming pool and

sewage

DRTVRAO MD 12

ANTIMICROBIAL MODES OF ACTION OF

DISINFECTANTS AND ANTISEPTICS

bull Denaturation of bacterial proteins by disrupting hydrogen and disulfide bonds

mdashmdash phenol (high conc) alcohol heavy-metal (high conc) acids alkalis aldehydes)

bull Damage to bacterial membrane (lipids andor proteins) causing leakage of intracellular molecules

mdashmdash phenol (low conc) surfactants dyes

bull Interference of bacterial enzyme and metabolism

mdashmdash oxidants heavy-metals (low conc) alkylating agents

DRTVRAO MD 13

bull Alkylating agent（烷化剂）

mdashmdash alkylating

proteins and nucleic

acids bull formalin (formaldehyde) mdashmdash

surface disinfection air

surgical instruments

bull glutaric dialdehydemdash high-

precision instruments

endoscopes

bull 50mgL epoxy ethane mdashmdash

surgical instruments and

dressing

ALKYLATING PROTEINS AND NUCLEIC ACIDS

DRTVRAO MD 14

bull Phenol and phenol derivatives

mdashmdash altering membrane permeability and denaturing proteins

bull 001 - 005 Chlorhexidine）mdashmdash vaginal wash OR hand-wash

bull 3 - 5 carbonic acid or 2 Lysol mdashmdash floor or surface disinfection

PHENOL AND PHENOL DERIVATIVES

DRTVRAO MD 15

bull Alcohols mdashmdash denaturing bacterial proteins and

membranes

bull 70 - 75 ethyl or isopropyl alcoholmdashmdash skin and thermometer disinfection

ndash ineffective against endospores and non-enveloped viruses

ALCOHOLS

DRTVRAO MD 16

bull Oxidants

mdashmdash oxidation protein precipitation

bull 3 peroxidemdashmdash small trauma wound skin mucosa

bull 02 - 1 peroxyacetic acidmdashmdash plastics glassware

bull 02 ndash 05 ppm chlorines mdashmdash water and swimming pool

bull 01 potassium permanganatemdashmdash skin

fruitsvegetables

DRTVRAO MD 17

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

ANTISEPTICS VERSUS DISINFECTANTS

Antiseptics Use on skin and mucous membranes to kill microorganisms

Not for use on inanimate objects

Disinfectants

Use to kill microorganisms on inanimate objects

Not for use on skin or mucous membranes

High-level versus low-level disinfectants

DRTVRAO MD 7

BEGINNING OF SCIENTIFIC ERA OF

STERILIZATION AND DISINFECTION

DRTVRAO MD 8

bull Process of reducing or

eliminating living

pathogenic

microorganisms in or

on materials so they

are no longer a health

hazard

For example use of alcohol before drug injection

DISINFECTION

DRTVRAO MD 9

bull Process of destroying all microbial forms A sterile object is one free of all microbial forms including bacterial spores

bull More thorough than disinfection

STERILIZATION

DRTVRAO MD 10

Soaps are sodium or

potassium salts of fatty

acids a natural product

Detergents instead are

artificial surfactants

While soaps are always

negatively charged some

detergents are negatively

charged while others are

positively charged

One example of a

positively charged

detergent are quaternary

ammonium compounds

(aka quats)

SOAP AND DETERGENTS

DRTVRAO MD 11

HALOGENS

Halogens are the seventh (VII) column of the periodic table of elements

Two halogens are regularly employed as antimicrobials Iodine and

Chloride

Iodine commonly used as an antiseptic against all microbes fungi and

viruses

Iodine It inhibits protein synthesis and oxidizes ndashSH groups of amino

acids

Chlorine Used as a disinfectant (10 bleach)

Chlorine Hypochlorous acid (HOCl) is a product formed in water that is

the active form of the disinfectant

Chlorine Applied in treatment of drinking water swimming pool and

sewage

DRTVRAO MD 12

ANTIMICROBIAL MODES OF ACTION OF

DISINFECTANTS AND ANTISEPTICS

bull Denaturation of bacterial proteins by disrupting hydrogen and disulfide bonds

mdashmdash phenol (high conc) alcohol heavy-metal (high conc) acids alkalis aldehydes)

bull Damage to bacterial membrane (lipids andor proteins) causing leakage of intracellular molecules

mdashmdash phenol (low conc) surfactants dyes

bull Interference of bacterial enzyme and metabolism

mdashmdash oxidants heavy-metals (low conc) alkylating agents

DRTVRAO MD 13

bull Alkylating agent（烷化剂）

mdashmdash alkylating

proteins and nucleic

acids bull formalin (formaldehyde) mdashmdash

surface disinfection air

surgical instruments

bull glutaric dialdehydemdash high-

precision instruments

endoscopes

bull 50mgL epoxy ethane mdashmdash

surgical instruments and

dressing

ALKYLATING PROTEINS AND NUCLEIC ACIDS

DRTVRAO MD 14

bull Phenol and phenol derivatives

mdashmdash altering membrane permeability and denaturing proteins

bull 001 - 005 Chlorhexidine）mdashmdash vaginal wash OR hand-wash

bull 3 - 5 carbonic acid or 2 Lysol mdashmdash floor or surface disinfection

PHENOL AND PHENOL DERIVATIVES

DRTVRAO MD 15

bull Alcohols mdashmdash denaturing bacterial proteins and

membranes

bull 70 - 75 ethyl or isopropyl alcoholmdashmdash skin and thermometer disinfection

ndash ineffective against endospores and non-enveloped viruses

ALCOHOLS

DRTVRAO MD 16

bull Oxidants

mdashmdash oxidation protein precipitation

bull 3 peroxidemdashmdash small trauma wound skin mucosa

bull 02 - 1 peroxyacetic acidmdashmdash plastics glassware

bull 02 ndash 05 ppm chlorines mdashmdash water and swimming pool

bull 01 potassium permanganatemdashmdash skin

fruitsvegetables

DRTVRAO MD 17

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

BEGINNING OF SCIENTIFIC ERA OF

STERILIZATION AND DISINFECTION

DRTVRAO MD 8

bull Process of reducing or

eliminating living

pathogenic

microorganisms in or

on materials so they

are no longer a health

hazard

For example use of alcohol before drug injection

DISINFECTION

DRTVRAO MD 9

bull Process of destroying all microbial forms A sterile object is one free of all microbial forms including bacterial spores

bull More thorough than disinfection

STERILIZATION

DRTVRAO MD 10

Soaps are sodium or

potassium salts of fatty

acids a natural product

Detergents instead are

artificial surfactants

While soaps are always

negatively charged some

detergents are negatively

charged while others are

positively charged

One example of a

positively charged

detergent are quaternary

ammonium compounds

(aka quats)

SOAP AND DETERGENTS

DRTVRAO MD 11

HALOGENS

Halogens are the seventh (VII) column of the periodic table of elements

Two halogens are regularly employed as antimicrobials Iodine and

Chloride

Iodine commonly used as an antiseptic against all microbes fungi and

viruses

Iodine It inhibits protein synthesis and oxidizes ndashSH groups of amino

acids

Chlorine Used as a disinfectant (10 bleach)

Chlorine Hypochlorous acid (HOCl) is a product formed in water that is

the active form of the disinfectant

Chlorine Applied in treatment of drinking water swimming pool and

sewage

DRTVRAO MD 12

ANTIMICROBIAL MODES OF ACTION OF

DISINFECTANTS AND ANTISEPTICS

bull Denaturation of bacterial proteins by disrupting hydrogen and disulfide bonds

mdashmdash phenol (high conc) alcohol heavy-metal (high conc) acids alkalis aldehydes)

bull Damage to bacterial membrane (lipids andor proteins) causing leakage of intracellular molecules

mdashmdash phenol (low conc) surfactants dyes

bull Interference of bacterial enzyme and metabolism

mdashmdash oxidants heavy-metals (low conc) alkylating agents

DRTVRAO MD 13

bull Alkylating agent（烷化剂）

mdashmdash alkylating

proteins and nucleic

acids bull formalin (formaldehyde) mdashmdash

surface disinfection air

surgical instruments

bull glutaric dialdehydemdash high-

precision instruments

endoscopes

bull 50mgL epoxy ethane mdashmdash

surgical instruments and

dressing

ALKYLATING PROTEINS AND NUCLEIC ACIDS

DRTVRAO MD 14

bull Phenol and phenol derivatives

mdashmdash altering membrane permeability and denaturing proteins

bull 001 - 005 Chlorhexidine）mdashmdash vaginal wash OR hand-wash

bull 3 - 5 carbonic acid or 2 Lysol mdashmdash floor or surface disinfection

PHENOL AND PHENOL DERIVATIVES

DRTVRAO MD 15

bull Alcohols mdashmdash denaturing bacterial proteins and

membranes

bull 70 - 75 ethyl or isopropyl alcoholmdashmdash skin and thermometer disinfection

ndash ineffective against endospores and non-enveloped viruses

ALCOHOLS

DRTVRAO MD 16

bull Oxidants

mdashmdash oxidation protein precipitation

bull 3 peroxidemdashmdash small trauma wound skin mucosa

bull 02 - 1 peroxyacetic acidmdashmdash plastics glassware

bull 02 ndash 05 ppm chlorines mdashmdash water and swimming pool

bull 01 potassium permanganatemdashmdash skin

fruitsvegetables

DRTVRAO MD 17

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

bull Process of reducing or

eliminating living

pathogenic

microorganisms in or

on materials so they

are no longer a health

hazard

For example use of alcohol before drug injection

DISINFECTION

DRTVRAO MD 9

bull Process of destroying all microbial forms A sterile object is one free of all microbial forms including bacterial spores

bull More thorough than disinfection

STERILIZATION

DRTVRAO MD 10

Soaps are sodium or

potassium salts of fatty

acids a natural product

Detergents instead are

artificial surfactants

While soaps are always

negatively charged some

detergents are negatively

charged while others are

positively charged

One example of a

positively charged

detergent are quaternary

ammonium compounds

(aka quats)

SOAP AND DETERGENTS

DRTVRAO MD 11

HALOGENS

Halogens are the seventh (VII) column of the periodic table of elements

Two halogens are regularly employed as antimicrobials Iodine and

Chloride

Iodine commonly used as an antiseptic against all microbes fungi and

viruses

Iodine It inhibits protein synthesis and oxidizes ndashSH groups of amino

acids

Chlorine Used as a disinfectant (10 bleach)

Chlorine Hypochlorous acid (HOCl) is a product formed in water that is

the active form of the disinfectant

Chlorine Applied in treatment of drinking water swimming pool and

sewage

DRTVRAO MD 12

ANTIMICROBIAL MODES OF ACTION OF

DISINFECTANTS AND ANTISEPTICS

bull Denaturation of bacterial proteins by disrupting hydrogen and disulfide bonds

mdashmdash phenol (high conc) alcohol heavy-metal (high conc) acids alkalis aldehydes)

bull Damage to bacterial membrane (lipids andor proteins) causing leakage of intracellular molecules

mdashmdash phenol (low conc) surfactants dyes

bull Interference of bacterial enzyme and metabolism

mdashmdash oxidants heavy-metals (low conc) alkylating agents

DRTVRAO MD 13

bull Alkylating agent（烷化剂）

mdashmdash alkylating

proteins and nucleic

acids bull formalin (formaldehyde) mdashmdash

surface disinfection air

surgical instruments

bull glutaric dialdehydemdash high-

precision instruments

endoscopes

bull 50mgL epoxy ethane mdashmdash

surgical instruments and

dressing

ALKYLATING PROTEINS AND NUCLEIC ACIDS

DRTVRAO MD 14

bull Phenol and phenol derivatives

mdashmdash altering membrane permeability and denaturing proteins

bull 001 - 005 Chlorhexidine）mdashmdash vaginal wash OR hand-wash

bull 3 - 5 carbonic acid or 2 Lysol mdashmdash floor or surface disinfection

PHENOL AND PHENOL DERIVATIVES

DRTVRAO MD 15

bull Alcohols mdashmdash denaturing bacterial proteins and

membranes

bull 70 - 75 ethyl or isopropyl alcoholmdashmdash skin and thermometer disinfection

ndash ineffective against endospores and non-enveloped viruses

ALCOHOLS

DRTVRAO MD 16

bull Oxidants

mdashmdash oxidation protein precipitation

bull 3 peroxidemdashmdash small trauma wound skin mucosa

bull 02 - 1 peroxyacetic acidmdashmdash plastics glassware

bull 02 ndash 05 ppm chlorines mdashmdash water and swimming pool

bull 01 potassium permanganatemdashmdash skin

fruitsvegetables

DRTVRAO MD 17

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

bull Process of destroying all microbial forms A sterile object is one free of all microbial forms including bacterial spores

bull More thorough than disinfection

STERILIZATION

DRTVRAO MD 10

Soaps are sodium or

potassium salts of fatty

acids a natural product

Detergents instead are

artificial surfactants

While soaps are always

negatively charged some

detergents are negatively

charged while others are

positively charged

One example of a

positively charged

detergent are quaternary

ammonium compounds

(aka quats)

SOAP AND DETERGENTS

DRTVRAO MD 11

HALOGENS

Halogens are the seventh (VII) column of the periodic table of elements

Two halogens are regularly employed as antimicrobials Iodine and

Chloride

Iodine commonly used as an antiseptic against all microbes fungi and

viruses

Iodine It inhibits protein synthesis and oxidizes ndashSH groups of amino

acids

Chlorine Used as a disinfectant (10 bleach)

Chlorine Hypochlorous acid (HOCl) is a product formed in water that is

the active form of the disinfectant

Chlorine Applied in treatment of drinking water swimming pool and

sewage

DRTVRAO MD 12

ANTIMICROBIAL MODES OF ACTION OF

DISINFECTANTS AND ANTISEPTICS

bull Denaturation of bacterial proteins by disrupting hydrogen and disulfide bonds

mdashmdash phenol (high conc) alcohol heavy-metal (high conc) acids alkalis aldehydes)

bull Damage to bacterial membrane (lipids andor proteins) causing leakage of intracellular molecules

mdashmdash phenol (low conc) surfactants dyes

bull Interference of bacterial enzyme and metabolism

mdashmdash oxidants heavy-metals (low conc) alkylating agents

DRTVRAO MD 13

bull Alkylating agent（烷化剂）

mdashmdash alkylating

proteins and nucleic

acids bull formalin (formaldehyde) mdashmdash

surface disinfection air

surgical instruments

bull glutaric dialdehydemdash high-

precision instruments

endoscopes

bull 50mgL epoxy ethane mdashmdash

surgical instruments and

dressing

ALKYLATING PROTEINS AND NUCLEIC ACIDS

DRTVRAO MD 14

bull Phenol and phenol derivatives

mdashmdash altering membrane permeability and denaturing proteins

bull 001 - 005 Chlorhexidine）mdashmdash vaginal wash OR hand-wash

bull 3 - 5 carbonic acid or 2 Lysol mdashmdash floor or surface disinfection

PHENOL AND PHENOL DERIVATIVES

DRTVRAO MD 15

bull Alcohols mdashmdash denaturing bacterial proteins and

membranes

bull 70 - 75 ethyl or isopropyl alcoholmdashmdash skin and thermometer disinfection

ndash ineffective against endospores and non-enveloped viruses

ALCOHOLS

DRTVRAO MD 16

bull Oxidants

mdashmdash oxidation protein precipitation

bull 3 peroxidemdashmdash small trauma wound skin mucosa

bull 02 - 1 peroxyacetic acidmdashmdash plastics glassware

bull 02 ndash 05 ppm chlorines mdashmdash water and swimming pool

bull 01 potassium permanganatemdashmdash skin

fruitsvegetables

DRTVRAO MD 17

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

Soaps are sodium or

potassium salts of fatty

acids a natural product

Detergents instead are

artificial surfactants

While soaps are always

negatively charged some

detergents are negatively

charged while others are

positively charged

One example of a

positively charged

detergent are quaternary

ammonium compounds

(aka quats)

SOAP AND DETERGENTS

DRTVRAO MD 11

HALOGENS

Halogens are the seventh (VII) column of the periodic table of elements

Two halogens are regularly employed as antimicrobials Iodine and

Chloride

Iodine commonly used as an antiseptic against all microbes fungi and

viruses

Iodine It inhibits protein synthesis and oxidizes ndashSH groups of amino

acids

Chlorine Used as a disinfectant (10 bleach)

Chlorine Hypochlorous acid (HOCl) is a product formed in water that is

the active form of the disinfectant

Chlorine Applied in treatment of drinking water swimming pool and

sewage

DRTVRAO MD 12

ANTIMICROBIAL MODES OF ACTION OF

DISINFECTANTS AND ANTISEPTICS

bull Denaturation of bacterial proteins by disrupting hydrogen and disulfide bonds

mdashmdash phenol (high conc) alcohol heavy-metal (high conc) acids alkalis aldehydes)

bull Damage to bacterial membrane (lipids andor proteins) causing leakage of intracellular molecules

mdashmdash phenol (low conc) surfactants dyes

bull Interference of bacterial enzyme and metabolism

mdashmdash oxidants heavy-metals (low conc) alkylating agents

DRTVRAO MD 13

bull Alkylating agent（烷化剂）

mdashmdash alkylating

proteins and nucleic

acids bull formalin (formaldehyde) mdashmdash

surface disinfection air

surgical instruments

bull glutaric dialdehydemdash high-

precision instruments

endoscopes

bull 50mgL epoxy ethane mdashmdash

surgical instruments and

dressing

ALKYLATING PROTEINS AND NUCLEIC ACIDS

DRTVRAO MD 14

bull Phenol and phenol derivatives

mdashmdash altering membrane permeability and denaturing proteins

bull 001 - 005 Chlorhexidine）mdashmdash vaginal wash OR hand-wash

bull 3 - 5 carbonic acid or 2 Lysol mdashmdash floor or surface disinfection

PHENOL AND PHENOL DERIVATIVES

DRTVRAO MD 15

bull Alcohols mdashmdash denaturing bacterial proteins and

membranes

bull 70 - 75 ethyl or isopropyl alcoholmdashmdash skin and thermometer disinfection

ndash ineffective against endospores and non-enveloped viruses

ALCOHOLS

DRTVRAO MD 16

bull Oxidants

mdashmdash oxidation protein precipitation

bull 3 peroxidemdashmdash small trauma wound skin mucosa

bull 02 - 1 peroxyacetic acidmdashmdash plastics glassware

bull 02 ndash 05 ppm chlorines mdashmdash water and swimming pool

bull 01 potassium permanganatemdashmdash skin

fruitsvegetables

DRTVRAO MD 17

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

HALOGENS

Halogens are the seventh (VII) column of the periodic table of elements

Two halogens are regularly employed as antimicrobials Iodine and

Chloride

Iodine commonly used as an antiseptic against all microbes fungi and

viruses

Iodine It inhibits protein synthesis and oxidizes ndashSH groups of amino

acids

Chlorine Used as a disinfectant (10 bleach)

Chlorine Hypochlorous acid (HOCl) is a product formed in water that is

the active form of the disinfectant

Chlorine Applied in treatment of drinking water swimming pool and

sewage

DRTVRAO MD 12

ANTIMICROBIAL MODES OF ACTION OF

DISINFECTANTS AND ANTISEPTICS

bull Denaturation of bacterial proteins by disrupting hydrogen and disulfide bonds

mdashmdash phenol (high conc) alcohol heavy-metal (high conc) acids alkalis aldehydes)

bull Damage to bacterial membrane (lipids andor proteins) causing leakage of intracellular molecules

mdashmdash phenol (low conc) surfactants dyes

bull Interference of bacterial enzyme and metabolism

mdashmdash oxidants heavy-metals (low conc) alkylating agents

DRTVRAO MD 13

bull Alkylating agent（烷化剂）

mdashmdash alkylating

proteins and nucleic

acids bull formalin (formaldehyde) mdashmdash

surface disinfection air

surgical instruments

bull glutaric dialdehydemdash high-

precision instruments

endoscopes

bull 50mgL epoxy ethane mdashmdash

surgical instruments and

dressing

ALKYLATING PROTEINS AND NUCLEIC ACIDS

DRTVRAO MD 14

bull Phenol and phenol derivatives

mdashmdash altering membrane permeability and denaturing proteins

bull 001 - 005 Chlorhexidine）mdashmdash vaginal wash OR hand-wash

bull 3 - 5 carbonic acid or 2 Lysol mdashmdash floor or surface disinfection

PHENOL AND PHENOL DERIVATIVES

DRTVRAO MD 15

bull Alcohols mdashmdash denaturing bacterial proteins and

membranes

bull 70 - 75 ethyl or isopropyl alcoholmdashmdash skin and thermometer disinfection

ndash ineffective against endospores and non-enveloped viruses

ALCOHOLS

DRTVRAO MD 16

bull Oxidants

mdashmdash oxidation protein precipitation

bull 3 peroxidemdashmdash small trauma wound skin mucosa

bull 02 - 1 peroxyacetic acidmdashmdash plastics glassware

bull 02 ndash 05 ppm chlorines mdashmdash water and swimming pool

bull 01 potassium permanganatemdashmdash skin

fruitsvegetables

DRTVRAO MD 17

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

ANTIMICROBIAL MODES OF ACTION OF

DISINFECTANTS AND ANTISEPTICS

bull Denaturation of bacterial proteins by disrupting hydrogen and disulfide bonds

mdashmdash phenol (high conc) alcohol heavy-metal (high conc) acids alkalis aldehydes)

bull Damage to bacterial membrane (lipids andor proteins) causing leakage of intracellular molecules

mdashmdash phenol (low conc) surfactants dyes

bull Interference of bacterial enzyme and metabolism

mdashmdash oxidants heavy-metals (low conc) alkylating agents

DRTVRAO MD 13

bull Alkylating agent（烷化剂）

mdashmdash alkylating

proteins and nucleic

acids bull formalin (formaldehyde) mdashmdash

surface disinfection air

surgical instruments

bull glutaric dialdehydemdash high-

precision instruments

endoscopes

bull 50mgL epoxy ethane mdashmdash

surgical instruments and

dressing

ALKYLATING PROTEINS AND NUCLEIC ACIDS

DRTVRAO MD 14

bull Phenol and phenol derivatives

mdashmdash altering membrane permeability and denaturing proteins

bull 001 - 005 Chlorhexidine）mdashmdash vaginal wash OR hand-wash

bull 3 - 5 carbonic acid or 2 Lysol mdashmdash floor or surface disinfection

PHENOL AND PHENOL DERIVATIVES

DRTVRAO MD 15

bull Alcohols mdashmdash denaturing bacterial proteins and

membranes

bull 70 - 75 ethyl or isopropyl alcoholmdashmdash skin and thermometer disinfection

ndash ineffective against endospores and non-enveloped viruses

ALCOHOLS

DRTVRAO MD 16

bull Oxidants

mdashmdash oxidation protein precipitation

bull 3 peroxidemdashmdash small trauma wound skin mucosa

bull 02 - 1 peroxyacetic acidmdashmdash plastics glassware

bull 02 ndash 05 ppm chlorines mdashmdash water and swimming pool

bull 01 potassium permanganatemdashmdash skin

fruitsvegetables

DRTVRAO MD 17

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

bull Alkylating agent（烷化剂）

mdashmdash alkylating

proteins and nucleic

acids bull formalin (formaldehyde) mdashmdash

surface disinfection air

surgical instruments

bull glutaric dialdehydemdash high-

precision instruments

endoscopes

bull 50mgL epoxy ethane mdashmdash

surgical instruments and

dressing

ALKYLATING PROTEINS AND NUCLEIC ACIDS

DRTVRAO MD 14

bull Phenol and phenol derivatives

mdashmdash altering membrane permeability and denaturing proteins

bull 001 - 005 Chlorhexidine）mdashmdash vaginal wash OR hand-wash

bull 3 - 5 carbonic acid or 2 Lysol mdashmdash floor or surface disinfection

PHENOL AND PHENOL DERIVATIVES

DRTVRAO MD 15

bull Alcohols mdashmdash denaturing bacterial proteins and

membranes

bull 70 - 75 ethyl or isopropyl alcoholmdashmdash skin and thermometer disinfection

ndash ineffective against endospores and non-enveloped viruses

ALCOHOLS

DRTVRAO MD 16

bull Oxidants

mdashmdash oxidation protein precipitation

bull 3 peroxidemdashmdash small trauma wound skin mucosa

bull 02 - 1 peroxyacetic acidmdashmdash plastics glassware

bull 02 ndash 05 ppm chlorines mdashmdash water and swimming pool

bull 01 potassium permanganatemdashmdash skin

fruitsvegetables

DRTVRAO MD 17

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

bull Phenol and phenol derivatives

mdashmdash altering membrane permeability and denaturing proteins

bull 001 - 005 Chlorhexidine）mdashmdash vaginal wash OR hand-wash

bull 3 - 5 carbonic acid or 2 Lysol mdashmdash floor or surface disinfection

PHENOL AND PHENOL DERIVATIVES

DRTVRAO MD 15

bull Alcohols mdashmdash denaturing bacterial proteins and

membranes

bull 70 - 75 ethyl or isopropyl alcoholmdashmdash skin and thermometer disinfection

ndash ineffective against endospores and non-enveloped viruses

ALCOHOLS

DRTVRAO MD 16

bull Oxidants

mdashmdash oxidation protein precipitation

bull 3 peroxidemdashmdash small trauma wound skin mucosa

bull 02 - 1 peroxyacetic acidmdashmdash plastics glassware

bull 02 ndash 05 ppm chlorines mdashmdash water and swimming pool

bull 01 potassium permanganatemdashmdash skin

fruitsvegetables

DRTVRAO MD 17

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

bull Alcohols mdashmdash denaturing bacterial proteins and

membranes

bull 70 - 75 ethyl or isopropyl alcoholmdashmdash skin and thermometer disinfection

ndash ineffective against endospores and non-enveloped viruses

ALCOHOLS

DRTVRAO MD 16

bull Oxidants

mdashmdash oxidation protein precipitation

bull 3 peroxidemdashmdash small trauma wound skin mucosa

bull 02 - 1 peroxyacetic acidmdashmdash plastics glassware

bull 02 ndash 05 ppm chlorines mdashmdash water and swimming pool

bull 01 potassium permanganatemdashmdash skin

fruitsvegetables

DRTVRAO MD 17

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

bull Oxidants

mdashmdash oxidation protein precipitation

bull 3 peroxidemdashmdash small trauma wound skin mucosa

bull 02 - 1 peroxyacetic acidmdashmdash plastics glassware

bull 02 ndash 05 ppm chlorines mdashmdash water and swimming pool

bull 01 potassium permanganatemdashmdash skin

fruitsvegetables

DRTVRAO MD 17

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

DISINFECTANT EFFECTIVENESS

DEPENDS ON MANY FACTORS

bull Concentration and quantity of disinfectant It is important to choose the proper concentration and quantity of disinfectant that is best suited to each situation

bull bull Contact time and temperature Sufficient time and appropriate temperature must be allowed for action of the disinfectant and may depend on the degree of contamination and organic matter load

bull bull Residual activity and effects on fabric and metal should be considered for specific situations

bull bull Application temperature pH and interactions with other compounds must be considered

bull bull Toxicity to the environment and relative safety to people that may be exposed

bull bull What about Cost

bull 5

DRTVRAO MD 18

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

bull Examples Benzyl-4-

chlorophenol Amyl phenol

Phenyl phenol

bull Advantages and

disadvantages good

general purpose

disinfectants not readily

inactivated

bull by organic matter active

against wide range of

organisms (including

mycobacterium) but not

sporicidal

PHENOLICS

DRTVRAO MD 19

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

PHENOL AS DISINFECTANT

bull Phenolic disinfectants are

effective against bacteria

(especially gram positive

bacteria) and enveloped

viruses They are not

effective against

nonenvelopedd viruses

and spores These

disinfectants maintain

their activity in the

presence of organic

material

DRTVRAO MD 20

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

PHENOL AS DISINFECTANT

bull They are not effective against nonenvelopedd viruses and spores These disinfectants maintain their activity in the presence of organic material This class of compounds is used for decontamination of the hospital environment including laboratory surfaces and noncritical medical items

DRTVRAO MD 21

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

PHENOL AS DISINFECTANT

bull Phenolics are not

recommended for semi

critical items because of

the lack of validated

efficacy data for many of

the available formulations

and because the residual

disinfectant on porous

materials may cause

tissue irritation even when

thoroughly rinsed

DRTVRAO MD 22

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

IODINE AND IODOPHOR

DISINFECTANTS

bull These compounds have been

incorporated in time release

formulations and in soaps

(surgical scrubs) Simple

iodine tinctures (dissolved in

alcohol) have limited cleaning

ability These compounds are

bactericidal sporicidal

virucidal and fungicidal but

require a prolonged contact

time

DRTVRAO MD 23

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

IODINE AND IODOPHOR

DISINFECTANTS

bull Besides their use as

an antiseptic Iodophor

have been used for the

disinfection of blood

culture bottles and

medical equipment

such as hydrotherapy

tanks thermometers

and endoscopes

DRTVRAO MD 24

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

IODINE AND IODOPHOR

DISINFECTANTS

bull The disinfective ability of

iodine like chlorine is

neutralized in the presence of

organic material and hence

frequent applications are

needed for thorough

disinfection Iodine tinctures

can be very irritating to

tissues can stain fabric and

be corrosive

DRTVRAO MD 25

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

ALCOHOLS

bull ldquoAlcohol refers to two water-soluble chemicals

ethyl alcohol and isopropyl alcohol These alcohols

are rapidly bactericidal rather than bacteriostatic

against vegetative forms of bacteria (Gram + and

Gram -) they also are tuberculocidal fungicidal

and virucidal against enveloped viruses Alcohols

are not effective against bacterial spores and have

limited effectiveness against nonenveloped viruses

DRTVRAO MD 26

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

ALCOHOLS bull Their cidal activity drops

sharply when diluted

below 50 concentration

and the optimum

bactericidal concentration

is in the range of 60-90

solutions in water

(volumevolume) The

antimicrobial activity of

alcohols can be attributed

to their ability to denature

proteins

DRTVRAO MD 27

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

ALCOHOLS

bull Higher

concentrations are

less effective as the

action of denaturing

proteins is inhibited

without the

presence of water

DRTVRAO MD 28

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

ALCOHOLS bull Alcohols are commonly

used topical antiseptics

They are also used to

disinfect the surface of

medical equipment

Alcohols require time to

work and they may not

penetrate organic

material

DRTVRAO MD 29

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

ALCOHOLS bull They also evaporate

rapidly which makes

extended exposure time

difficult to achieve unless

the items are immersed

Alcohol irritates tissues

They are generally too

expensive for general use

as a surface disinfectant

DRTVRAO MD 30

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

GAINING IMPORTANCE IN HAND WASHING

WITH ALCOHOLS

bull The use of either ethyl

alcohol or isopropyl alcohol

in a 60-90 solution has

recently gained wide

acceptance in health care

settings as hand antiseptics

They can be used as a

reasonable substitute for

handwashing as long as

hands are not visibly soiled

DRTVRAO MD 31

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

HYPOCHLORITES

bull They have a broad

spectrum of

antimicrobial activity

are unaffected by

water hardness are

inexpensive and fast

acting and have a low

incidence of serious

toxicity

DRTVRAO MD 32

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

DRTVRAO MD 33

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

HYPOCHLORITES bull Other disadvantages of

hypochlorites include

corrosiveness to metals in

high concentrations (gt500

ppm) inactivation by

organic matter discoloring

or ldquobleachingrdquo of fabrics

and release of toxic

chlorine gas when mixed

with ammonia or acid

DRTVRAO MD 34

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

HYPOCHLORITES

bull Hypochlorites can eliminate both enveloped and

nonenveloped viruses if used in correct dilution

and contact time They are also is effective against

fungi bacteria and algae but not spores

Household bleach is typically diluted using 150

with water (1000ppm) for surface disinfection

Bleach solutions have been recommended for use

in both hospitals and the community as

disinfecting solutions

DRTVRAO MD 35

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

HYPOCHLORITES MOST RECOMMENDED

IN

bull They are included

in most

recommendation

for

decontamination

of hepatitis and

AIDS viruses

DRTVRAO MD 36

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

HYPOCHLORITES

bull Hypochlorites are also

the agent of choice in

disinfecting surfaces used

for food preparation or in

bathrooms Organic

material such as feces or

blood inactivate chlorine

based disinfectants

therefore surfaces must

be clean before their use

DRTVRAO MD 37

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

HYPOCHLORITES

bull Chlorinated drinking

water should not

exceed 6 to 10 ppm of

free chlorine with the

lower value being in

continuous flow or low

volume reservoir

systems

DRTVRAO MD 38

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

HIGH LEVEL DISINFECTANTS

DRTVRAO MD 39

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

HYDROGEN PEROXIDE

bull Peroxides such as hydrogen peroxide are often used as antiseptics to clean wounds The activity of peroxides is greatest against anaerobic bacteria Hydrogen peroxide at high concentrations is in some cases is damaging to tissues resulting in a prolonged healing time It is useful for cleaning surgical sites after closure but use sparingly to avoid penetrating suture lines which would inhibit healing

DRTVRAO MD 40

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

HYDROGEN PEROXIDE

bull Stabilized hydrogen

peroxides can be used to

disinfect environmental

surfaces The literature

contains several accounts

of the properties

germicidal effectiveness

and potential uses for

stabilized hydrogen

peroxide in the hospital

setting DRTVRAO MD 41

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

FORMALDEHYDE

bull Gluteraldehydes are very

potent disinfectants

which can be highly toxic

Use them only as a last

resort and then under

trained supervision in a

well-ventilated setting and

with appropriate personal

protective equipment

DRTVRAO MD 42

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

FORMALDEHYDE

bull Formaldehyde is used as a disinfectant and sterilant both in the liquid and gaseous states Formaldehyde is sold and used principally as a water-based solution called formalin which is 37 formaldehyde by weight The aqueous solution is bactericidal tuberculocidal fungicidal virucidal and sporicidal DRTVRAO MD 43

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

FORMALDEHYDE bull Formaldehyde should be handled

in the workplace as a potential carcinogen with an employee exposure standard that limits an 8 hour time-weighted average exposure to a concentration of

075 ppm For this reason employees should have limited direct contact with formaldehyde and these considerations limit its role in sterilization and disinfection processes

DRTVRAO MD 44

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

GLUTARALDEHYDE

bull Aldehydes have a wide germicidal spectrum Gluteraldehydes are bactericidal virucidal fungicidal sporicidal and parasiticidal They are used as a disinfectant or sterilant in both liquid and gaseous forms They have moderate residual activity and are effective in the presence of limited amounts of organic material

DRTVRAO MD 45

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

ETHYLENE OXIDE

DRTVRAO MD 46

bull Ethylene oxide also called oxirane is the

organic compound with the formula C2H4O It is

a cyclic ether This means that it is composed of

two alkyl groups attached to an oxygen atom in

a cyclic shape (circular) This colorless

flammable gas with a faintly sweet odor is the

simplest epoxide a three-membered ring

consisting of two carbon and one oxygen atom

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

bull Highly effective

against most

microbes

bull Highly diffusive

bull Compatible with a

wide variety of

materials in devices

and packaging

ETHYLENE OXIDE ADVANTAGES

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

bull Complex process

bull Longer turn-around times

bull BI Testing

bull Residual dissipation

bull Safety concerns

bull Flammable

bull Explosive

bull OSHA concerns

bull Carcinogen

bull EPA concerns

bull Emissions

ETHYLENE OXIDE DISADVANTAGES

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

ORTHO-PHTHALALDEHYDE

bull Ortho-phthalaldehyde (OPA) is a chemical sterilant similar to Gluteraldehydes with similar antimicrobial activity OPA has several potential advantages compared to Gluteraldehydes It has excellent stability over a wide pH range (pH 3-9) is not a known irritant to the eyes and nasal passages does not require exposure monitoring has a barely perceptible odor and requires no activation OPA like Gluteraldehydes has excellent material compatibility

DRTVRAO MD 49

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

bull A potential disadvantage of

OPA is that it stains

proteins gray (including

unprotected skin) and thus

must be handled with

caution However skin

staining would indicate

improper handling that

requires additional training

andor personal protective

equipment (PPE) (gloves

eye and mouth protection

fluid-resistant gowns)

ORTHO-PHTHALALDEHYDE

DRTVRAO MD 50

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

bull Per acetic or peroxyacetic acid is characterized by a very rapid action against all microorganisms A special advantage of per acetic acid is it has no harmful decomposition products (ie acetic acid water oxygen hydrogen peroxide) and leaves no residue It remains effective in the presence of organic matter and is sporicidal even at low temperatures

PER ACETIC ACID

DRTVRAO MD 51

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

PER ACETIC ACID

bull It is used in

automated

machines to

chemically sterilize

medical surgical

and dental

instruments (eg

endoscopes

arthroscopies)

DRTVRAO MD 52

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

PER ACETIC ACID AND HYDROGEN

PEROXIDE

bull Two chemical sterilants are available that

contain per acetic acid plus hydrogen

peroxide (008 per acetic acid plus 10

hydrogen peroxide [no longer marketed]

023 per acetic acid plus 735 hydrogen

peroxide) The bactericidal properties of

per acetic acid and hydrogen peroxide

have been established

DRTVRAO MD 53

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

PER ACETIC ACID AND HYDROGEN PEROXIDE

USEFUL IN HEM DIALYZERS

bull Findings demonstrated

that this product

inactivated all

microorganisms with the

exception of bacterial

spores within 20 minutes

The combination of per

acetic acid and hydrogen

peroxide has been used

for disinfecting hem

dialyzers

DRTVRAO MD 54

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

QUATERNARY AMMONIUM

COMPOUNDS

bull The quaternaries are good cleaning agents but

high water hardness and materials such as cotton

and gauze pads may make them less microbicidal

because these materials absorb the active

ingredients As with several other disinfectants

(eg phenolic Iodophor) gram-negative bacteria

have been found to survive or grow in these

preparations

DRTVRAO MD 55

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

QUATERNARY AMMONIUM

COMPOUNDS

bull They are not effective against non-enveloped viruses fungi and bacterial spores QA disinfectants carry a very strong positive charge that makes good contact with negatively charged surfaces This characteristic makes most very good cleaning agents QA compounds are generally low in toxicity but prolonged contact can be irritating The quaternaries are commonly used in ordinary environmental sanitation of noncritical surfaces such as floors furniture and walls

DRTVRAO MD 56

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

GAS PLASMA

STERILIZATION

DRTVRAO MD 57

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

bull Plasma is a fourth state of matter which is distinguishable from liquid solid or gas In nature plasma is widespread in outer space

bull Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles

bull Can be used for hand sterilization

WHAT IS GAS PLASMA

DRTVRAO MD 58

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

HOW GAS PLASMA WORKS

bull Many particles are in the form of free radicals

bull A free radical is an Atom with an unpaired

electron and is a highly reactive species

bull The mechanism of action of this device is the

production of free radicals within a plasma field

that are capable of interacting with essential cell

components ie is enzymes and nucleic acids And

thereby disrupt the metabolism of microorganisms

DRTVRAO MD 59

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

GAS PLASMA - STERILIZATION

bull Plasma sterilization

operates differently

because of its specific

active agents which are

ultraviolet (UV) photons

and radicals (atoms or

assembly of atoms with

unpaired electrons

therefore chemically

reactive eg O and OH

respectively

DRTVRAO MD 60

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

bull Destruction by UV

irradiation of the genetic

material of the

microorganism this is a

statistical process requiring

a sufficient number of

lesions of the DNA strands

bull Erosion of the

microorganism atom by

atom through intrinsic

photo desorption

BASIC MECHANISMS OF PLASMA

STERILIZATION

DRTVRAO MD 61

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

ADVANTAGE OF THE PLASMA

METHOD

bull An advantage of the plasma method is the possibility under appropriate conditions of achieving such a process at relatively low temperatures (le50 degC) preserving the integrity of polymer-based instruments which cannot be subjected to autoclaves and ovens Furthermore plasma sterilization is safe both for the operator and the patient in contrast to EtO

DRTVRAO MD 62

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

HYDROGEN PEROXIDE STERILIZATION

OFFERS FAST CYCLE TIMES

bull Benefits of gas plasma (vaporized hydrogen peroxide) sterilization are fast cycle times the absence of toxic residuals and a low-moisture environment not exceeding 50ordmC

DRTVRAO MD 63

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

NEW CDC GUIDELINES

FACTORS RELATED TO INFECTION RISK

bull Endoscope contamination accounts for more health care related infections than any other medical instrument and is responsible for consequences ranging from bacterial colonization to death

DRTVRAO MD 64

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

DISINFECTION AND STERILIZATION ARE

AFFECTED BY

bull Initial cleaning of the device

bull Physical complexity of the device

Biofilms and microbial load

bull Microbe type and quantity

bull HLD exposure time and concentration

DRTVRAO MD 65

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoBiofilms are microbial

communities that are

tightly attached to

surfaces and cannot be

easily removedBacteria

within biofilms are up to

1000 times more

resistant to antimicrobials

than are the same

bacteria in suspension

DRTVRAO MD 66

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

BIOFILMS INTERFERE IN EFFECTIVE

ANTIMICROBIAL ACTION

bull ldquoOne multistate investigation found that 239 of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew ge100000 colonies of bacteria after completion of all disinfection and sterilization procedures

DRTVRAO MD 67

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

GUIDELINE EXCERPTS

INFECTION RISKS

bull ldquoMultiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization

bull Failure to comply with scientifically-based guidelines has led to numerous outbreaks

DRTVRAO MD 68

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

NO DISINFECTANT IS SUBSTITUTE FOR

THE FOLLOWING PROCEDURES

bull 1048766 Hand washing (hand hygiene)

bull 1048766 The use of personal protective equipment (eg gloves) when handling blood body

bull substances excretions and secretions

bull 1048766 Appropriate handling of patient care equipment and soiled linen

bull 1048766 The prevention of needle sticksharp injuries

bull 1048766 Environmental cleaning

bull 1048766 Appropriate handling of waste and

bull 1048766 Taking care of yourself (eg immunization)

DRTVRAO MD 69

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

HAN

YET ndash NO SUBSTITUTE FOR HAND WASHING

Immediately on arrival at work

Before and after examining each client

After touching anything that might be contaminated

After handling specimens

Before putting on gloves for clinical procedures

After removing gloves

After using the toilet or latrine

Before leaving work

DRTVRAO MD 70

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71

bull Programme Created by DrTVRao MD for

Medical and Paramedical professionals in the

Developing World

bull Email

bull doctortvraogmailcom

DRTVRAO MD 71