Final answer:
The most common transmission route for HAIs is airborne transmission through coughing or sneezing. Another common route is the fecal-oral route through contaminated water or undercooked meat. There are also other routes, such as healthcare-associated transmission, bloodstream transmission, and transmission of STIs.
Step-by-step explanation:
Airborne transmission is the most common transmission route for healthcare-associated infections (HAIs). This occurs when pathogens in droplets expelled from an infected person's respiratory system during coughing or sneezing are inhaled by nearby individuals, who then become new hosts for the pathogens. Diseases like the flu and the common cold can spread through this route. Another common route is the fecal-oral route, which is often seen in developing countries through contaminated water or undercooked meat.
In addition to airborne and fecal-oral transmission, there are other routes for HAIs, such as healthcare-associated transmission through contaminated medical equipment, transmission through the bloodstream via catheters or wounds, and transmission of sexually transmitted infections (STIs) through sexual behaviors and body fluids.