Which of the following is an example of a reservoir for an infection?

• A. A patient who is infected
• B. A disinfected surface
• C. The habitat of the infectious agent where it lives, grows, and reproduces
• D. A sterile instrument

Answer: (C)

The main concept is that a reservoir is the place where an infectious agent can survive, thrive, and multiply, providing a continual source for transmission. The statement describing the habitat where the agent lives, grows, and reproduces fits this definition exactly, so it’s the best example of a reservoir. A patient who is infected can harbor and shed organisms and thus become a source of infection, but the term reservoir emphasizes the location that sustains the agent. A disinfected surface and a sterile instrument are not reservoirs because they no longer harbor live organisms. Understanding reservoirs helps inform infection control measures like cleaning, disinfection, sterilization, and environmental controls to interrupt transmission.