The Chain of The Chain of InfectionInfection

1.The various ways infection can be transmitted.

2. The ways the infection chain can be broken.

As healthcare professionals, it is As healthcare professionals, it is important to understand two facts about important to understand two facts about

infection:infection:

There are six links There are six links in the chain of infection:in the chain of infection: 1. Causative agent2. Source or reservoir3. Portal of exit4. Mode of transmission5. Portal of entry6. Susceptible host

1st - The Infectious 1st - The Infectious AgentAgent

-Any disease-causing microorganism (pathogen)

2nd - The Reservoir 2nd - The Reservoir HostHost

-The organism in which the infectious microbes

reside

Hosts that do not show any outward signs or symptoms of a disease, but are still capable of transmitting the disease are known as carriers.

What are What are ““Carrier Carrier Hosts?Hosts?””

3rd - The Portal of Exit3rd - The Portal of Exit

-Route of escape of the pathogen from the reservoir

Examples: respiratory secretions, blood exposure, breaks in skin

• The way a causative agent can be transmitted to a host.

4th - Mode of 4th - Mode of TransmissionTransmission

5th - The Portal of Entry5th - The Portal of Entry

• A way for the causative agent (pathogen) to enter a new host.

• Examples:Respiratory System (inhalation)Gastrointestinal System (ingestion)Urinary & Reproductive Tracts

(sexual contact)Breaks in Protective Skin Barrier

6th - The Susceptible Host6th - The Susceptible Host

• An individual who can contract the disease.

• The support of pathogen life and its reproduction depend on the degree of the host’s resistance.

• Organisms with strong immune systems are better able to fend off pathogens.

• Organisms with weakened immune systems are more vulnerable to the support and reproduction of pathogens.

Interrupting the Chain of Infection

• Pathogen Identification• Asepsis and Hygiene• Control Portals of Entry

Pathogen Identification

• Identify the infectious (causative) agent (pathogen) in order to treat it appropriately.

Asepsis and Hygiene

• Potential hosts and carriers must practice asepsis and maintain proper personal hygieneWhat is the most important thing we do as healthcare workers to practice asepsis?

Handwashing

Control Portals of Exit (Prevention)

• Healthcare personnel must practice standard precautions! (Control body secretions and wash hands according to protocol.) Proper Handwashing Disinfection & Sterilization Techniques Isolation of infected patients Not working when contagious

5. Protect Portal of 5. Protect Portal of EntryEntry

Healthcare professionals must make sure that ports of

entry are not subjected to pathogens.

(nose, mouth, eyes, urinary tract, open wounds, etc.)

6. Recognition of 6. Recognition of Susceptible HostSusceptible Host

Healthcare professionals must recognize and protect high-risk patients. Cancer Patients

•AIDS Patients

•Transplant Patients

•Infants

•Elderly Patients

The Chain of Infection Simply Stated

Human Immunodeficiency Virus

• HIVHIV• Attacks the body’s immune systemAttacks the body’s immune system• Permanent conditionPermanent condition• Spread through:Spread through:• - Sexual secretions- Sexual secretions• - Blood- Blood• - Pregnancy or childbirth- Pregnancy or childbirth• Limited life outside the bodyLimited life outside the body• Not transmitted via casual contactNot transmitted via casual contact• 1.1 million people in U.S.1.1 million people in U.S.• Acquired Immune Deficiency Syndrome Acquired Immune Deficiency Syndrome

(AIDS)(AIDS)

HIV Symptoms

• Immunosuppressed• Appetite loss• Weight loss• Recurrent fever• Night sweats• Skin rashes• Diarrhea• Fatigue• Swollen lymph nodes

Acquired Immune Deficiency Syndrome (AIDS)

• Caused by HIVCaused by HIV• Unable to fight off many cancers and Unable to fight off many cancers and

infectionsinfections• NO cureNO cure• Antiretroviral Therapy (ART)Antiretroviral Therapy (ART)• PreventionPrevention• - Abstinence- Abstinence• - Eliminate sharing - Eliminate sharing • * Drug equipment (needles)* Drug equipment (needles)• * Personal items (razors, * Personal items (razors,

toothbrushes)toothbrushes)• * ALWAYS incorporate standard precautions* ALWAYS incorporate standard precautions

Hepatitis B

• Swelling and inflammation of the liverSwelling and inflammation of the liver• EXTREMELY contagiousEXTREMELY contagious• Most common of manyMost common of many• Can lead to:Can lead to:• - Liver failure- Liver failure• - Cirrhosis (scarring)- Cirrhosis (scarring)• - Liver cancer- Liver cancer• Transmission:Transmission:• - Blood- Blood• - Unprotected sex- Unprotected sex• - Unsterile needles- Unsterile needles• - Childbirth of infected mother- Childbirth of infected mother

Healthcare Workers

• Increased risk Increased risk • The CDC recommends vaccinationsThe CDC recommends vaccinations• Federal law requires employers to provide Federal law requires employers to provide

vaccinationsvaccinations• FREE of charge to employee.FREE of charge to employee.• HBV vaccine is effective and safeHBV vaccine is effective and safe• Vaccine series:Vaccine series:• - Initial injection- Initial injection• - 1 month- 1 month• - 6 months- 6 months• - Titer (4-6 weeks after last injection)- Titer (4-6 weeks after last injection)

HIV, AIDS, HBV

• OSHA’s Bloodborne Pathogen OSHA’s Bloodborne Pathogen StandardStandard

- Designed to protect employees- Designed to protect employees

in the healthcare fieldin the healthcare field

““Remember--breaking the chain of Remember--breaking the chain of infection is the responsibility infection is the responsibility

of each healthcare professional.of each healthcare professional.””