Blog Post

Interesting and Relevant Articles on Infection Control

What is the epidemiologic triangle?

Written by Admin
Posted On May 15, 2024

The US Centers for Disease Control and Prevention, or CDC, created the epidemiologic triangle to explain how an infectious agent can moves efficiently along the chain of infection and infect a large number of people. The triangle represents the interactions between host, pathogen, and environment.

On the triangle, the host is the person who is exposed to the pathogen. To help fight pathogens, each person has natural barriers such as intact skin, respiratory cilia, and gastric acid and a powerful immune system. When these characteristics are healthy and effective, a potential host can often fight off a pathogen. However, when these characteristics are ineffective or in a weakened state, a person’s chances of falling ill as a result of an infection greatly increase.

The pathogen—the infectious agent that can cause disease is the second point of the epidemiologic triangle. The characteristics of a pathogen determine how effectively it infects people with disease. These characteristics include:

  • Infectivity: The ability of the pathogen to infect a person and to spread easily from host to host
  • Pathogenicity: The potential of the pathogen to produce disease in a host
  • Virulence: The extent to which the pathogen is dangerous
  • Size: The size of the pathogen to which the host is exposed
  • Route of exposure: The way in which the pathogen is transmitted
  • Duration of exposure: The length of time to which the host is exposed to the pathogen

The environment the circumstances in which the host and pathogen come together is the third point of the epidemiologic triangle. The factors related to the environment that influence the results of a host’s exposure to a pathogen include contamination of the environment, fomites (i.e., objects, such as doorknobs, that may be contaminated), and contamination of equipment.

When the elements of the epidemiologic triangle are all aligned under given circumstances, a pathogen can move freely along the chain of infection and cause disease in a larger number of people. Moreover, the environment can either facilitate or hinder the spread of infections. Contaminated environments, fomites, and inadequate infection control measures can all contribute to increased transmission rates. By understanding and addressing these elements, public health authorities and healthcare professionals can develop effective strategies to prevent and control infectious diseases, ultimately reducing the burden of illness on populations.

Your Cart
Your shopping cart is currently empty!

Don't miss out on our amazing training products – start adding items today!

Close