Cryptosporidiosis is a diarrhel disease caused by microscopic parasites of the genus Cryptosporidium. Once an animal or person is infected, the parasite lives in the intestine and passes as an oocyst in the stool.
The oocysts are protected by an outer shell that allows the parasite to remain infective outside the body for long periods of time. The same outer shell-the oocyst wall-makes the parasite resistant to chlorination.
The most common symptom of cryptosporidiosis is watery diarrhea. Other symptoms include dehydration, weight loss, stomach cramps or pain, fever, nausea and vomiting. Both the disease and the parasite are commonly known as crypto.