[Cryptosporidiosis--a typical environmental parasitosis]

The article reviews the problems on epidemiology of cryptosporidiosis and gives a detailed description of the massive waterborne outbreak in Milwaukee (Wisconsin, USA) associated with a break in filtration capacity of a public water supply. The authors emphasize the need for high-quality diagnostic procedures as current coprodiagnostic microscopical techniques seemed to fail to detect Cryptosporidium oocysts.