Cryptosporidium Parvum

Cryptosporidium parvum is one of several single-celled parasites that cause cryptosporidiosis, a disease of the mammalian intestinal tract most often marked by acute, watery diarrhea that can occur as often as ten to fifteen times a day in severe cases, along with loss of appetite, nausea, vomiting and abdominal discomfort; less commonly it affects the lungs, liver or gallbladder. It spreads when a host swallows its hardy, sporulated cysts, typically through contaminated water or food, with as few as about 130 cysts able to establish infection in a healthy person. The infection is usually self-limiting in people with normal immune function but can become life-threatening in those who are immunocompromised, such as people with AIDS or those on immune-suppressing therapy.