About Cryptosporidium

Cryptosporidiosis is an infection caused by the parasite Cryptosporidium parvum.

Cryptosporidium is a common cause of both foodborne and waterborne disease in the United States. Healthcare professionals may also refer to the parasite and its disease as “crypto” or “crypto infection.”

Symptoms may include stomach cramps or pain, watery diarrhea (the most common symptom), fever, nausea, vomiting, dehydration, malaise, malnutrition and weight loss (in more severe cases). Symptoms may occur 1 to 10 days after infection and will last for approximately 2 weeks in healthy individuals. Symptoms can be much more severe and even life-threatening in the immuno-compromised.

Cryptosporidium infection occurs when an individual eats food, drinks water, or comes into contact with surfaces or objects contaminated by the parasite or its oocysts (a dormant stage in which the parasite is resistant to many adverse environmental conditions allowing it to survive outside the body). Cryptosporidium lives in the intestines of infected people or animals and is excreted in feces. Infection, therefore, is the fecal to oral route.

Common ways of contracting Cryptosporidiosis include: eating uncooked food contaminated with Cryptosporidium; swallowing contaminated recreational water (e.g., pools, spray parks, ponds) or drinking water; or putting objects or fingers in the mouth that have come into contact with the feces of an infected person or animal or a contaminated surface.

To diagnose Cryptosporidiosis, your doctor will ask you to provide a stool sample, which will be examined for the presence of the Cryptosporidium parasite and its oocysts. You may be asked to provide several samples since detecting the parasite or its oocysts can be difficult. For more information, please refer to Symptoms and Complication of Cryptosporidiosis.