Infection control: a reservoir is defined as a place where infectious agents live?

• A. Reservoir
• B. Portal of exit
• C. Mode of transmission
• D. Susceptible host

Answer: (A)

Reservoirs are places where infectious agents live and multiply, acting as sources from which the organism can spread to others. This can be a person, animal, plant, soil, water, or even contaminated surfaces or medical equipment that harbor microbes. The reservoir provides a persistent source of infection so transmission to a susceptible host can occur.

The other terms describe different parts of the transmission process: a portal of exit is how the agent leaves the reservoir (for example, through coughing or bodily fluids), a mode of transmission is how it travels to a new host (direct contact, droplets, airborne, vectors), and a susceptible host is someone at risk because they lack immunity or defenses. Because a reservoir is specifically the place where the infectious agent lives, it is the best match.