This message provides a set of actions for installations to follow in the event of fecal contamination of a swimming pool. Maintaining sanitary water quality in a swimming pool is undoubtedly a difficult challenge. Proper filtration and disinfection of the water are required to provide a safe swimming environment. Even under optimum conditions, swimming pools can harbor a variety of pathogenic organisms harmful to swimmers, such as bacteria, viruses, and protozoa.
Chlorine disinfection controls virtually all the organisms.
The protozoan Cryptosporidium is an exception. It is a waterborne pathogen that is highly resistant to chlorine, and has a high infectivity rate. Transmission is via the fecal-oral route, and it can be spread from animal to human or human to human. One mode of transmission of cryptosporidiosis is fecal accidents in swimming pools. There is a possibility that swimmers will ingest the contaminated water and contract cryptosporidiosis, a diarrheal illness.