1. Adapted by Dana Cashion HS1, Fall 2016
Chain of Infection
Adapted by Dana Cashion
HS1, Fall 2016

2. Principles of Infection DHO Ch14 pg 355 and HCST Ch3 pg 75
Chain of Infection
Signs and Symptoms of Infection
Nosocomial Infections
Asepsis
Chapter 3

3. Chain of Infection
Chain of infection contains 6 elements. If broken, infection will not occur.
Infectious Agent
Portal of Exit
Reservoir
Mode of Transmission
Portal of Entry
Susceptible Host
Chapter 3

4. Chain of Infection (cont.)
Infectious Agent. Microorganisms that normally reside on the skin.
Reservoir. Residence of microorganisms.
Fomites are nonliving materials that house microorganisms.
Chapter 3

5. Chain of Infection (cont.)
Portal of Exit.
Respiratory tract.
Skin.
Blood.
Gastrointestinal tract.
Mucous membrane.
Mode of Transmission.
How a pathogen is transmitted.
Can be through direct contact or airborne droplet.
Hand washing is one of the most effective means of preventing the spread of pathogens.
Chapter 3

6. Chain of Infection (cont.)
Portal of Entry.
Respiratory tract, mucous membranes, and gastrointestinal tract are common.
Damaged skin.
Susceptible Host.
One that is capable of being infected.
Microorganisms must be present in large enough quantity to be virulent.
The host must be susceptible.
Individuals with an immunity to certain pathogens will not be susceptible.
Chapter 3