In the chain of infection, the portal through which a pathogen leaves the host is called

• A. Pathogen
• B. Reservoir
• C. Portal of Exit
• D. Portal of Entry

Answer: (C)

The exit path a pathogen uses to leave the infected person is called the portal of exit. This is the part of the chain of infection that determines how the organism is shed into the environment and can reach a new susceptible host. For example, respiratory droplets exit through the mouth or nose during coughing or sneezing, blood can leave via a wound, and pathogens can exit with feces or urine or through skin lesions. This exit route is different from the portal of entry, which is how a new host is infected (such as the respiratory tract, GI tract, or broken skin). It’s also different from the reservoir, which is the environment or host in which the pathogen normally lives and multiplies. So, the term that names the path by which a pathogen leaves the host is portal of exit.