In the chain of infection, which is the second component?

• A. The causative agent
• B. The reservoir
• C. The portal of exit
• D. The mode of transmission

Answer: (B)

Infection spread relies on a sequence of links, and the second link is the reservoir—the place where the germ can live and multiply. The pathogen has to survive somewhere outside of a single moment of transfer, and the reservoir can be a person, an animal, dirt or water, or a contaminated surface or object. This is why the reservoir is essential: it supports the pathogen’s survival long enough to reach another host. After the reservoir comes how the germ exits the source, how it travels to a new person, how it enters the new person, and whether the new person is susceptible. Understanding this helps with prevention—reducing or eliminating the reservoir, through things like cleaning and proper infection control, breaks the chain and stops spread.