Activity Industry Sector
Health Science and Medical Technology

Activity Originally Created By: Pamela Hildebrandt

Chain of Infection and the Ways to Break the Links

Part of Lesson Plan: Everyone Is Contagious

Activity Overview / Details

Outline the CHAIN OF INFECTION to the students:  In order for disease to occur and spread from one individual to another, certain conditions must be present.  These conditions are commonly called the "chain of infection'. The parts of the chain include : 

Causative agent:  a pathogen...such as a bacterium or virus that can cause disease.

Reservoir:  an area where the causative agent can live. Some common  reservoirs include the humand body, animals, the environment, and formites  (or contaminated objects).

Portal of exit:  a way for the causative agent to escape from the reservoir.

Mode of Transportation:  a way for the causative agent to travel from one reservoir to another host...pathogens may have more than one of these.  For example-person to person...first by a sneeze, then by a handshake when a person covers their mouth (yech).

Portal of Entry:  A way for the for the causative agent to enter a new host.....mucous membranes, breaks in the skin, respiratory tract, digestive system, genitourinary tract, and the circulatory tract. If the immune system is not strong enough to repel the pathogen the body will contract the disease.

Susceptible host:  a person likely to get an infection or disease usually because  of weak body defenses.

Healthcare workers must constantly be aware of the parts in the chain of infection.  If any part of the chain is eliminated, the spread of disease or infection is eliminated.  A healthcare worker who is aware of this can follow practices to interrrupt or break this chain and prevent the transmission of disease.  It is important  to remember that pathogens are everywhere....preventing their transmission is a continuous process.

Ask students to identify ways or measures they can take to prevent or stop processes within the chain of infection. 

Discuss how the equipment that has been laid out stops the chain of infection. Have students participate in a quick write describing why it is important as a future healthcare worker that they learn about the chain of infection; ways they stop or prevent the chain of infection in their daily lives as well as things they can do in the future to prevent the spread of infection.