Infection control

The Chain of The Chain of InfectionInfection

Tri Star Med PrepTri Star Med PrepJ. Nelson RN, CMAJ. Nelson RN, CMA

As healthcare As healthcare professionals, it professionals, it is important tois important to understand two understand two

things about things about infectioninfection:

1.The various ways infection can be transmitted

2. The ways the infection chain can be broken

There are six There are six links links

in the Chain in the Chain of Infection of Infection ::

11stst- Causative Agent- Causative Agent

-Any disease-causing microorganism (pathogen)

2nd - The Reservoir Host2nd - The Reservoir Host

-The organism in which the infectious microbes reside.

-Common reservoirs are: human body, animals, fomites, & environment.

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 “Carrier Hosts”What are “Carrier Hosts”

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

-Route of escape of the pathogen from the reservoir.

Examples: respiratory secretions, blood, urine, feces, sexual secretions, wound drainage.

4th - The Route of 4th - The Route of TransmissionTransmission

-Method by which the pathogen gets from the reservoir to the new host

Transmission may occur through:

Direct Contact: Person-to-Person…contaminated hands are the most

common

What other means of direct transmission are there?What other means of direct transmission are there?

Air

Indirect Contact: as in Indirect Contact: as in the case of inanimate objects the case of inanimate objects transmitting the pathogen. Such as:transmitting the pathogen. Such as:

InsectsVector: animal or insect that transmits the pathogen from infected to noninfectied individuals. Can you think of others?Can you think of others?

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

-Route through which the pathogen enters its new host

Respiratory System

inhala

tion

inhala

tion

Gastrointestinal Systemin

gesti

on

inge

stion

Urinary & Reproductive TractsSex

ual

Sexual

co

ntact

conta

ct

Or across Or across the placentathe placenta

Breaks in Protective Skin Barrier

6th - The6th - The Susceptible HostSusceptible Host

-The organism that accepts the pathogen

The support of pathogen life & its reproduction depend on the degree

of the host’s resistance.

Organisms with strong immune Organisms with strong immune systems are better able to fend off systems are better able to fend off

pathogens. pathogens.

What are some What are some

body defenses thatbody defenses that

defend a healthy body?defend a healthy body?

Organisms with weakened immune Organisms with weakened immune systems are more vulnerable to the systems are more vulnerable to the

support & reproduction of pathogens.support & reproduction of pathogens.

Can you think of Can you think of examples?examples?

-The essential part of patient care & self-protection.

How to interrupt the Chain of How to interrupt the Chain of Infection:Infection:

1. Pathogen 1. Pathogen IdentificationIdentification

-Identification of infectious agent & appropriate treatment

2. Asepsis & Hygiene2. Asepsis & Hygiene

-Potential hosts & carriers must practice

asepsis & maintain proper personal hygiene

Asepsis: free from infectionAsepsis: free from infection

3. Control Portals of Exit3. Control Portals of Exit

-Healthcare personnel must practice standard precautions:

Standard precautions: Standard precautions:

Precautions for all body fluids.Precautions for all body fluids.

(Control body secretions & wash hands according to protocol.)

4. Prevent a Route of 4. Prevent a Route of TransmissionTransmission

-Prevent direct or indirect contact by:

1. Proper handwashing

2. Disinfection & sterilization techniques

3. Isolation of infected patients

4. Using techniques to prevent transmission your pathogens.

5. Protect Portal of 5. Protect Portal of EntryEntry

-Health professionals must make sure that ports of entry are not

subjected to pathogens.

Use of handwashing and personal protective equipment as needed.

6. Recognition of 6. Recognition of Susceptible HostSusceptible Host

-Health professionals must recognize & protect high-risk patients

•Cancer Patients

•AIDS Patients

•Transplant Patients

•Infant & Elderly Patients

Remember--breaking the chain of Remember--breaking the chain of infection is the responsibility infection is the responsibility of each health professional.of each health professional.