Infectious Disease Epidemiology Program

Cryptosporidiosis Summary

Cryptosporidiosis is an infection most frequently associated with contaminated water. In 1993, 400,000 individuals became ill in Milwaukee due to the contamination of public drinking water. In 1997 cryptosporidiosis associated with exposure to a water sprinkler fountain at a Minnesota zoo caused widespread illness.

The disease is caused by a parasite which lives in the intestines of animals and infected humans. Feces containing the parasite may contaminate the ground or water sources. The parasite may live for long periods of time in the environment due to a protective outer covering. It is resistant to many chlorine-based disinfectants, increasing the risk of transmission in pool settings. If an individual who is infected swims in a pool, fecal contamination of the water may occur and result in transmission to other swimmers who ingest small quantities of water.

Fifty-six cases were reported in Maine in 2007. This number continues a trend of yearly increased reported cases of the illness. The median age of cases was 34 years old. Sixty-three percent of the cases reported were female. Residents of thirteen counties were reported with cryptosporidiosis with no cases reported from Cumberland, Androscoggin and Oxford counties. The highest rate of occurrence was in Lincoln County (14.4 per 100,000 population), Piscataquis County (11.6 per 100,000 population) and Aroostook County (11.1 per 100,000 population). The incidence in Maine was above the US rate possibly due to the rural and farming nature of the state. Almost 61% of the cases had some kind of animal contact.

Three small outbreaks were identified in Maine in July of 2007. There were 11 confirmed cases associated with these outbreaks. These clusters involved transmission that occurred in a school, family and swimming pool setting.

Preventive measures include the practice of good hand hygiene around farm animals and discouraging any persons from swimming when they have diarrheal illnesses