What type of host is most likely to become infected?

The most likely type of host to become infected is the susceptible host. This is because a susceptible host lacks sufficient immunity or defenses against pathogens, making them more vulnerable to infection. Individuals in this category may have weakened immune systems due to various factors such as age, underlying health conditions, or insufficient vaccination.

Infectious agents require a susceptible environment to thrive and spread. When these pathogens come into contact with a susceptible host, the likelihood of invasion and subsequent infection significantly increases.

The other categories—immune hosts, infected hosts, and carrier hosts—are less likely to fall into this definition of vulnerability. Immune hosts have defenses that actively fight infections; infected hosts already carry pathogens, meaning they are not new infections; and carrier hosts might harbor pathogens without showing symptoms, thereby not fitting the profile of a new infection risk. Thus, the concept of susceptibility is central to understanding infection control and prevention strategies.