The Portal of Exit for Pathogens

Question

The portal of exit for pathogens:
A) is always the same as the portal of entry.
B) is always different from the portal of entry.
C) may or may not be the same as the portal of entry.
D) is a critical requirement if the pathogen is to cause disease.
E) is lacking in almost all human diseases.

Accepted Answer

The portal of exit for pathogens may or may not be the same as the portal of entry. It depends on the specific pathogen and the route of infection. For example, respiratory pathogens such as the flu virus may exit the body through coughing or sneezing (portal of exit) and enter the new host through inhalation (portal of entry). However, fecal-oral pathogens such as Salmonella may exit the body through diarrhea (portal of exit) and enter a new host through contaminated food or water (portal of entry).