Cryptosporidium

Abstract

Cryptosporidium spp. are protozoan parasites that inhabit the brush borders of the gastrointestinal and respiratory epithelium of various vertebrates, causing enterocolitis, diarrhea, and cholangiopathy in humans. Cryptosporidium spp. are well‐recognized water and foodborne pathogens in industrialized nations, having caused many outbreaks of human illness. Cryptosporidium spp. are intracellular protozoan parasites that primarily infect epithelial cells of the intestine and biliary ducts, especially the ileum and colon. The distribution of Cryptosporidium parvum and Cryptosporidium hominis in humans is a reflection of the role of different transmission routes in cryptosporidiosis epidemiology. Cryptosporidiosis in immunocompromised persons, including patients with HIV, is frequently associated with chronic, life‐threatening diarrhea. In clinical laboratories, Cryptosporidium spp. in stool specimens are commonly detected by microscopic examinations of oocysts, immunologic detection of antigens, and nucleic acid amplification testing. Genotyping and subtyping have been used in characterizations of Cryptosporidium infections, especially in cryptosporidiosis surveillance and outbreak investigations.