Infectious diarrhea can contain hundreds of millions of germs in a single fecal accident. Many pools use one filtration system for several pools. This causes water from many pools to mix quickly, and distribute germs throughout connected pools in a very short amount of time. If other patrons then swallow the contaminated water, they may become infected and develop diarrhea or other illnesses. Since many illnesses can be spread by swallowing just a few germs, it is possible that a single diarrheal accident can contaminate water throughout the largest pool or waterpark.
Skin infections are the most common infections spread through hot tubs and spas.
The increased temperature of the water in hot tubs and spas can cause the chlorine to evaporate more rapidly than in swimming pools. As a result, chlorine or other disinfectant levels in hot tubs and spas need to be checked and adjusted more regularly than in swimming pools. Skin infections should not be transmitted if the water quality is appropriately maintained and monitored. Diarrhea can be caused by many different germs. It can last from a few days to weeks.