Infectious agent: Cryptosporidium species (Cryptosporidium hominis, Cryptosporidium parvum, and others)
Description of illness: Cryptosporidiosis is caused by the protozoan parasite Cryptosporidium. Infection causes acute, watery diarrhea which can last up to 4 weeks, often in a relapsing and remitting pattern. Ingestion of parasites from fecally contaminated water, soil, food or surfaces leads to infection. Infected people excrete the parasite in their stool at the onset of symptoms up to several weeks after symptoms resolve. In immunocompromised persons, cryptosporidiosis can cause chronic disease and life-threatening malabsorption.