Overview

Cryptosporidium infection (cryptosporidiosis) is an illness caused by tiny, one-celled cryptosporidium parasites. When cryptosporidia (krip-toe-spoe-RID-e-uh) enter your body, they travel to your small intestine and then burrow into the walls. Later, they're shed in your feces.

In most healthy people, a cryptosporidium infection produces a bout of watery diarrhea. The infection usually goes away within a week or two. If you have a compromised immune system, a cryptosporidium infection can become life-threatening without treatment.

You can help prevent a cryptosporidium infection by practicing good hygiene and avoiding swallowing water from pools, recreational water parks, lakes and streams.