Which collection of portals of exit is correct?

• A. Respiratory; Gastrointestinal; Genitourinary tracts; Breaks in skin; Blood and tissue
• B. Respiratory only
• C. Gastrointestinal only
• D. Skin only

Answer: (A)

Portals of exit are the routes pathogens use to leave a host and reach new people. The major exits include the respiratory tract (droplets from coughing, sneezing, or talking), the gastrointestinal tract (vomit or feces), the genitourinary tract (urine and genital secretions), breaks in the skin (wounds or ulcers), and blood or tissue (bloodborne or tissue fluids). This broad set captures the common ways infections are transmitted in real life. Limiting exit to just one system, as some options do, misses other important routes and isn’t sufficient to describe how pathogens spread.