Abstract
Protozoa of the genus Cryptosporidium are common parasites of domestic and wild animals-mammals, birds, reptiles, and fishes. The invasive forms are thick-walled oocysts, which can be present in water supplies, on fruits, vegetables, or in the soil contaminated with feces. In this work, we describe three cases of middle-aged persons with massive Cryptosporidium hominis infection and chronic diarrhea with no immunological abnormalities and no history of previous travels to tropical countries. The lesions discovered during colonoscopy within the large intestine-cryptitis and the histopathological changes were related to massive cryptosporidiosis. All these statements indicate necessity of parasitological stool examination in cases with chronic diarrhea in which no etiological agents are detected, but not only in HIV positive individuals. Parasite's eradication leads to symptom disappearance as well as improvement of histopathological mucosa alterations.