Cryptosporidiosis is an infection caused by the protozoan parasite, Cryptosporidium parvum. The parasite infects cells that line the surface of the small intestine and causes intestinal irritation and diarrhea. This infection is usually mild and self-limited in normal hosts, but symptoms may be severe and long lasting in HIV-infected persons who have deficient immune function. Widespread outbreaks of cryptosporidiosis have occurred and have been associated with the contamination of municipal water supplies. At present, there is no universally effective drug that can prevent or treat this infection.

The recommendations for prevention of cryptosporidiosis transmission include avoiding contaminated food and water; washing hands after contact with pets, gardening, contact with soil, and exposure to calves, lambs, or excrement; and avoiding drinking or swimming in water from lakes or rivers. Boiling water for one minute and/or the use of absolute one-micron (1-m m) filters, reverse osmosis filters, or NSF (National Sanitation Foundation) standard #53 filters for cyst removal provide the greatest protection from cryptosporidia exposure.

Common-use therapeutic pools in community, clinic, or hospital settings should also be avoided. Due to the lack of standardized maintenance and infection control policies across settings, the risk of infection can be equal to that in recreational sites. HIV-infected persons should, therefore, avoid common-use therapeutic pools where accidental ingestion of cryptosporidiosis oocysts can occur. Healthcare providers should review and consider these guidelines when recommending aquatic therapy as an exercise regimen or as part of a physical therapy program for HIV-infected patients.


1. Centers for Disease Control and Prevention. 1999 USPHS/ISDA Guidelines for the Prevention of Opportunistic Infections in Persons Infected with Human Immunodeficiency Virus: US Public Health Service (USPHS) and Infectious Diseases Society of America (IDSA). MMWR 1999; 48: 1-66.