INFECTION CONTROL

Understanding the basic principles of infection control is essential for any healthcare worker in any field of health care.

Our essential question is: How are diseases transmitted and

what are the main ways to prevent disease transmission?

Principles of Infection Control

Microorganism (or microbe) – small, living organism that is not visible to the naked eye.

Found everywhere in the environment, including on and in the human body

Nonpathogens – microorganism that is not capable of causing disease

Pathogens – microorganisms that cause infection and disease

Microorganisms can be beneficial in one body system and pathogenic in another body system

EX: E. Coli – digestive system – normal flora

urinary system - infection

To grow and reproduce, microorganisms need: Warm environment - body temp ideal Dark environment Source of food Source of moisture Aerobic organisms require oxygen Anaerobic organisms live and reproduce in

absence of oxygen Human body is ideal supplier of all

requirements of microorganisms

Main Classes of Microorganisms

Bacteria Protozoa Fungi Rickettsiae Viruses Helminths

Group Work

Each group will be assigned a pathogen in which they will become experts on.

Describe pathogen How are they classified? If possible, describe their shape? What diseases does this pathogen

cause? What is some other interesting info you

would like to share?

Bacteria

Simple one-celled organisms Multiply rapidly Classified by shape and arrangement Cocci Bacilli Spirilla Antibiotics are used to kill bacteria

BacteriaCocci

Round or spherical in shape If occurs in pairs – diplococci Cause diseases such as gonorrhea,

meningitis, pneumonia If occur in chains – streptococci Causes diseases such as strep throat

and rheumatic fever If occur in clusters - staphylococci

BacteriaCocci (cont’d – Staphylcocci)

Most common pyogenic (pus-producing) microorganisms.

Cause infections such as boils, wound infections, and toxic shock.

BacteriaBacilli

Rod-shaped bacteria Occur singly, in pairs, in chains Many contain flagella (threadlike

projections similar to tails – allow to move)

Have ability to form spores (thick- walled capsules) when conditions for growth are poor.

In spore form, bacilli extremely difficult to kill

BacteriaBacilli (cont’d)

Causes diseases such as tuberculosis, tetanus, pertussis, botulism, diphtheria, typhoid

Bacteria(Spirilla)

Comma shaped and corkscrew shaped

Causes diseases such as syphilis and cholera

Application:

1. Divide paper in thirds2. Label the first column Cocci Bacteria,

second column Bacilli Bacteria, third column Spirilla Bacteria.

3. Draw a diagram of each type of bacterial shape indicating 4 types of cocci, 3 types of bacilli, and 3 types of spirilla

4. Label diagrams5. List at least 5 diseases caused by cocci

and bacilli, and 2 diseases caused by spirilla

Protozoa

One-celled animal like organism Usually found in decayed materials

and contaminated water, animal or bird feces, insect bites

Many contain flagella to allow them to move freely

Cause diseases such as malaria, amebic dysentary, trichomonas (STD) , African sleeping sickness

Protozoa (Malaria)

Fungi

Small, plant-like organisms Live on dead organic matter Yeasts and molds are 2 common forms Causes diseases such as ringworm,

athlete’s foot, thrush, yeast vaginitis Antibiotics do not kill fungi Antifungal medicines - expensive,

long course of treatment, may cause liver damage

Rickettsiae

Parasitic microorganisms (cannot live outside the cells of another organism)

Found in fleas, ticks, lice, and mites and transmitted to humans by the bites of the insects

Causes diseases such as Rocky Mountain Spotted Fever

Treat with antibiotics

Viruses

Smallest microorganism– visible only with electron microscope

Cannot reproduce unless inside another living cell

Spread from human to human by blood and other body secretions

Can be resistant to disinfectants Antibiotics not effective

Virus(cont’d)

Causes diseases such as common cold, measles, mumps, chickenpox, herpes, warts, influenza, polio

3 diseases of major concern to healthcare worker:

Hepatitis BHepatitis CAIDS

New and different viruses emerge constantly because viruses are prone to mutating and changing genetic information.

Viruses that infect animals can mutate to infect humans – often fatally

Examples: SARS (severe acute respiratory infection), West Nile Virus, monkeypox, Ebola

HIV and Flu Viruses

Viruses of Special Concernto the Healthcare Worker

Hepatitis B Hepatitis C AIDS

Hepatitis B

Caused by HBV virus Transmitted by blood, serum and other

secretions Affects liver – can lead to destruction of

liver cells Can remain active for several days in

dried blood Vaccine available – expensive – series of 3 By law, employers must provide vaccine

to healthcare worker for free

Hepatitis C

Caused by HCV virus Transmitted by blood or blood-containing

fluids No vaccine available Patients often asymptomatic or mild flu

symptoms Can cause liver damage Extremely difficult to destroy Can remain active for several days in

dried blood

AIDS

Acquired Immune Deficiency Syndrome

Caused by HIV (human immunodeficiency virus)

Suppresses immune system Cannot fight off cancers or infections

that would not normally affect healthy person

No cure No vaccine

Microorganisms need certain things to grow and reproduce: Most prefer a warm environment – body temp

Most prefer darkness Most need food Most need moisture

Aerobic organisms – are organisms which require oxygen to live

Anaerobic organisms – do not require oxygen

Microorganisms can produce toxins: Toxins = poisons Ex: tetanus produces a toxin that

damages the CNS (central nervous system)

Helminths

Multicellular parasitic organisms Called worms or flukes Transmitted to humans when

humans ingest the eggs or larvae in contaminated food, ingest meat contaminated with worms, or the worm penetrates the skin.

Examples of Helminths:

Hookworms – attach to small intestine and can infect heart and lungs

Ascariasis – live in small intestine and can cause obstruction of the intestine

Trichinella spiralis – causes trichinosis contracted by eating raw or inadequately cooked pork

Enterobiasis (pinworms) mainly affects young children

Hookworm in intestine

Hookworm beneath skin

ascriasis

Trichinella spiralis

4 Classifications of Infectious Diseases

Endogenous Exogenous Nosocomial Opportunistic

Endogenous - infection /disease originates in body . Ex: tumor, congenital abnormality

Exogenous – infection/disease originates outside body. Ex: pathogenic organisms that invade body

Nosocomial infection – infection acquired by an individual in a healthcare facility. Ex: staph

Opportunistic – occurs when the body’s defenses are weak. Ex: Kaposi’s sarcoma

Chain of Infection:

For diseases to occur and spread from one individual to another, certain conditions must be met… Chain of Infection

Causative agent Reservoir Portal of exit Mode of transmission Portal of entry Susceptible host

Causative Agent:

A pathogen: Bacteria Virus Fungi Protozoa Rickettsiae HelminthWhat causes the infection/disease?

Reservoir:

A place where the pathogen can live: Human body Animals Environment Fomites (objects contaminated with

infectious material) Ex: door knobs, linens, instruments, etc

Portal of Exit:

A way to escape from the reservoir where it has been growing urine Feces Saliva Tears Blood Draining wounds Mucous discharge

Mode of Transmission:

Way it can be transmitted to another reservoir or host where it can live. Direct person to person contact Direct contact with body secretion

containing pathogen Ex: contaminated hands Indirect contact such as food, air, soil,

insects, feces, clothing, instruments and equipment

Portal of Entry:

Way to enter a new reservoir or host Breaks in skin Breaks in mucous membranes Respiratory tract Digestive tract Circulatory system

If the defense mechanisms of the body are intact and functioning, a human can frequently fight off the causative agent and not contract the disease.

Susceptible Host:

Person likely to get an infection

Application:

Using your textbook, identify 8 Body Defenses that work to prevent a causative agent from entering the human body.

Give an example of each Identify how each defense

mechanism prevents the causative agent from entering the body

Body Defenses

Mucous membranes Cilia Coughing and sneezing Hydrochloric acid – in stomach Tears in the eye Fever Inflammation (WBC destroy

pathogens) Immune response (antibodies)

Scenario:

Flu is caused by the influenza virus. Anyone can get the flu, which is a viral infection that attacks the respiratory system including your nose, throat, bronchial tubes and lungs. You’re especially at risk if you’re older, have diabetes, chronic heart disease or an impaired immune system. Someone you know has the flu, coughs and sneezes and then you touch something they’ve handled. That’s why the flu spreads anywhere people congregate…schools, cruise ships, day cares, etc.

Identify the:

Causative agent Reservoir Portal of exit Mode of transmission Portal of entry Susceptible host

E. coli is short for Escherichia coli—a germ that causes severe cramps and diarrhea. E. coli is a leading cause of bloody diarrhea. The symptoms are worse in children and older people, and especially in people who have another illness. E. coli infection is more common during the summer months and in northern states.Healthy beef and dairy cattle may carry the E. coli germ in their intestines. The meat can get contaminated with the germ during the slaughtering process. When beef is ground up, the E. coli germs get mixed throughout the meat.The most common way to get this infection is by eating undercooked hamburgers. You can be infectedwith the E. coli germ if you don’t use a high enough temperature to cook your beef, or if you don’t cook it long enough. When you eat undercooked beef, the germs enter your stomach and intestines.

If any part of the chain of infection is eliminated, the spread of disease or infection will be stopped.

Healthcare workers must understand chain of infection to interrupt or break the chain and prevent spreading of disease.

Pathogens are everywhere ….preventing their transmission is an ongoing process

Ways to Break Chain of Infection

Contamination – organisms and pathogens are present

Aseptic techniques – maintaining cleanliness, and eliminating or preventing contamination

Examples of common aseptic techniques: Handwashing Good personal hygiene Disposable gloves Proper cleaning of instruments Thorough cleaning of environment

Levels of Aseptic Control

Antisepsis – antiseptics prevent growth of pathogens….not effective against spores or viruses. Can be used on skin (alcohol, betadine)

Disinfection – process that destroys or kills pathogens…sometimes effective against spores or viruses. Usually used on objects and not skin (disinfectants such as bleach)

Sterilization – destroys all microorganisms including spores and viruses (autoclave)

How to use an Autoclave

Application:

1. Draw the chain of infection2. Label each of the 6 sections of the

chain of infection3. Identify 3 ways to break each

section of the chain of infection

Bioterrorism

Bioterrorism is the use of microorganisms or biological agents as weapons to infect humans.

Major concern of biological agents used not only in wars, but also against unsuspected civilians (ex: mail attack with anthrax)

Could cause an epidemic and public health emergency

Every healthcare worker must be alert to the threat of bioterrorism

Application:

Discussion of high priority agents that have been identified as potential bioterrorism agents

Handwashing

Handwashing is the most important method used to practice aseptic technique.

Most effective way to prevent spread of infection.

Hands are perfect medium for the spread of pathogens.

Proper handwashing helps prevent and control spread of pathogens AND protects health worker from disease and illness.

When should you wash hands?

Before and after every patient contact

Anytime hands become contaminated during procedure

Before applying and immediately after removing gloves

CDC recommendations for handwashing: Regular handwashing – soap and water;

routine cleansing of hands when hands are visibly dirty or soiled with blood/body fluids

Antiseptic handwashing – antimicrobial soap and water; before invasive procedures, critical care units, specific organism transmission based precautions

Antiseptic handrubs – alcohol based hand cleaners – ONLY if hands are not visibly dirty and are not soiled with blood/body fluids

Principles of Handwashing

Soap Warm water Friction Clean all surface areas Point fingertips downward Use paper towels to turn faucet off

and on Clean nails also

Proper Handwashing Tips:

Soap – preferably dispenser – sudsy action/alkali content removes germs

Warm water – creates better lather than cold Friction – rubs off pathogens from skin

surface Clean all surface area of hands Point fingertips downward Dry paper towels to turn faucet on and off –

pathogens can travel through wet paper towel

Clean nails – brush or rubbing against palms

Soap

Used as a cleansing agent Aid in removal of germs through

sudsing and alkali content Pathogens trapped in soap suds and

rinsed away Liquid soap better than bar soap

Warm water

Less damage to skin than hot water Increases lather of soap better than

cold water

Friction

Must use friction - rubs off pathogens from surface of skin

Rub hands together using friction for approximately 20 seconds.

Clean all Surfaces

Clean all surfaces of hands – including palms, back and tops of hands, between fingers.

Nails

Nails must be cleaned with an orange/cuticle stick, brush, or rubbing the nails against the palm of the opposite hand.

Nails must be kept short to prevent scratching the skin, injuring patients, breaking through gloves.

Point Fingertips Downward

Keep fingertips pointed downward. Downward direction prevents water from going up forearms and then running down to contaminate clean hands.

Turn faucet off with dry paper towels

Dry paper towels must be used to turn faucet off. This prevents the contamination of the hands from pathogens on the faucet. Pathogens can travel easier through a wet paper towel than a dry paper towel.

Application:

Head to sinks to practice!

Standard Precautions

Standard Precautions – rules developed by the CDC to prevent the spread of infection

Every body fluid and every patient is considered a potential source of infection

OSHA developed:Bloodborne Pathogen StandardNeedlestick Safety Act

Application:

Read pg 377 Bloodborne Pathogen Standard

What are the 3 pathogens of major concern to healthcare workers?

Who created the Bloodborne Pathogen Standard?

What is PPE and what is an employer’s responsibility regarding PPE?

Application:

Read pg 377 Needlestick Safety Act Who developed the Needlestick

Safety Act? Why was this act passed? List 4 requirements of employers

regarding the Needlestick Safety Act. Give an example of each.

Standard Precautions

Basic rules of standard precautions: Hand hygiene Gloves Gowns Masks and eye protection Sharps Spills and splashes Resuscitation devices

Cont’d

Waste and linen disposal injuries

PPE

PPE – Personal Protective Equipment

Donning PPE

Gown Mask Goggles Gloves

Removing PPE

Gloves Gown Eyewear Mask

Application:

Read pgs 385—387 Sterilizing with Autoclave

Read pgs. 392-393 Using Chemicals for Disinfecting

Read pgs. 394-395 Cleaning with an Ultrasonic Cleaner

Describe each method.

Sterile Technique

Sterile = free from all pathogens Contaminated = pathogens present Sterile field – never reach across a sterile

field

What is the difference between clean and sterile?

Create a double bubble map comparing and contrasting using an autoclave vs. disinfecting with chemicals.

How to don sterile gloves

Transmission-Based Isolation Procedures Communicable disease – a disease

which is caused by a pathogen which can easily be transmitted to others.

Read pg 408 What is the difference between a

pandemic and an epidemic

Epidemic – occurs when communicable disease spreads rapidly from person to person and affects a large number of people at the same time

Pandemic – exists when the outbreak of disease occurs over a wide geographical area and a effect a large portion of the population

Transmission-Based Isolation Precautions Methods or techniques of caring for

people with communicable diseases Ex: TB, whooping cough, wound

infections Standard Precautions are used on all

patients Transmission –Based Isolation

techniques are used to provide extra protection against specific diseases.

The type of transmission –based isolation precaution used depends on the diseaes

Application:

Read pgs.409-413 Create a double bubble map which

compares and contrasts 2 types of transmission-based isolation precautions

Airborne Precautions

Patients who are infected with pathogens transmitted by airborne droplet nuclei

Ex: measles (rubella), varicella (chicken pox), TB

Precautions: door kept closed, healthcare providers and visitors wear HEPA mask

Pt wears surgical mask if leaves room

Droplet Precautions

Pt infected with pathogens transmitted by large-particle droplets expelled during coughing, sneezing, talking,etc

Ex: flu (influenza), meningitis, pneumonia

Private room Masks

Contact Precautions

Pt infected with pathogens that can be easily transmitted by either direct or indirect contact

Ex: gastrointestinal, respiratory, skin or wound infections

Private room, gloves, gown, linens changed daily

Reverse Isolation

Methods used to protect certain patients from microorganisms

Used mainly for immunocompromised pts

Ex: transplant pts, chemotherapy , severely burned pts, weak immune system

Place in room that has been cleaned and disinfected, gloves, gown, mask, frequent disinfecting of room, special filters may be used to purify air.

Group Work to Demonstrate Working in a Hospital Isolation Unit

Divide into 7 groups

Reader Recorder Reporter

Group 1: Donning Isolation Garments

Group 2: Transfer food Group 3: dispose of leftover food Group 4: transfer of soiled linens Group 5: transfer trash Group 6: transfer equipment Group 7: Removing Isolation

Garments