In the chain of infection, the susceptible individual who can acquire infection is referred to as what?

• A. New host
• B. Reservoir
• C. Pathogen
• D. Portal of entry

Answer: (A)

Infection risk hinges on the host being susceptible. In the chain of infection, the person who can acquire infection is the host who is new to the pathogen—someone not yet infected and lacking sufficient immunity or defenses to prevent infection. This “new” host is the one the pathogen may enter and establish an infection, continuing the transmission sequence.

The other terms refer to different parts of the chain: the reservoir is where the pathogen lives, the pathogen is the microorganism itself, and the portal of entry is the route the organism uses to get into the body. So identifying the susceptible, newly exposed person as the new host best captures who is at risk of acquiring infection.