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Cryptosporidiosis (often called "crypto") is a diarrheal disease caused by a one-celled parasite called Cryptosporidium parvum. Few people had heard of crypto until 1993, when over 400,000 people in Milwaukee, Wisconsin, became ill after their drinking water became contaminated with the parasite. Large outbreaks and isolated cases of crypto have been identified in Oregon as well. This has focused attention on determining and reducing the risk for cryptosporidiosis from community and municipal water supplies.

For persons with suppressed immune systems, for example persons with AIDS, some cancers, or recent organ transplants, the infection may persist indefinitely, and symptoms may be more severe.

Disease Reporting

What is required?

Health-care providers and clinical laboratories:
Health-care providers and clinical laboratories are required to report cases and suspect cases of cryptosporidiosis to local health departments within one working day of identification. 

Cases are subject to restriction on school and day-care attendance, food handling, and patient care for the duration of any diarrhea and/or vomiting.

Disease reporting form for health-care practitioners (PDF 42K)

See our disease reporting page for information on how to report and for telephone numbers of local health departments.

For Local Health Departments:
Cryptosporidiosis: Investigative guidelines (pdf)
Cryptosporidiosis: Case Report Form (pdf)


Cyrptosporidiosis statistics (pdf) from the 2015 Oregon Communicable Disease Summary


See Also