What is the term for the chain of infection concept?

• A. A fixed sequence that cannot be interrupted.
• B. A method of preventing infection by breaking one or more links in the chain: infectious agent, reservoir, portal of exit, transmission, portal of entry, susceptible host.
• C. An illness that spreads through air only.
• D. A gene therapy approach

Answer: (B)

Understanding how infections spread relies on recognizing a sequence of linked steps. The chain of infection involves six components: the infectious agent, a reservoir where the agent lives, a portal of exit, a mode of transmission, a portal of entry, and a susceptible host. The key idea is that preventing disease comes from interrupting one or more of these links, which stops the spread. That’s why the option describing a method of preventing infection by breaking one or more links in the chain—covering all the possible links—best fits the concept. It highlights practical ways to block transmission at different stages, like hygiene, barriers, proper sanitation, and protecting susceptible individuals. The other choices miss the main idea: one suggests the chain can’t be interrupted, another narrows spread to air only, and the last points to an unrelated field.