The Chain of Infection

First, let us recap how infectious diseases are transmitted. Transmission usually occurs when an infectious agent is transmitted from an infected individual to a susceptible person. The traditional epidemiologic triad model holds that infectious diseases result from the interaction of agent, host, and environment. More specifically, transmission occurs when the agent leaves its reservoir or host through a portal of exit, is conveyed by some mode of transmission, and enters through an appropriate portal of entry to infect a susceptible host. This sequence is called the chain of infection (see Figure 1 for further illustration)2.

Figure 1 The chain of infection is a set of 6 intertwined links that allow for communicable diseases to spread3.

Post a comment

Leave a Comment