Cryptosporidium: an important cause of gastrointestinal disease in immunocompetent patients.

A twelve month survey was undertaken to determine the incidence of Cryptosporidium associated diarrhoeal disease in immunocompetent individuals in Taranaki. The parasite was detected in faecal samples from 54 (4.2%) of 1273 patients. The highest incidence (7.2%) occurred in those aged 1 to 15 years. All patients presented with a self limiting gastrointestinal illness. Of the 54 cases, 40 (74%) were diagnosed in the spring and early to mid-summer. Direct contact with farm animals was the probable source of infection in the majority of cases. It is recommended that clinical laboratories routinely screen faecal samples from patients with diarrhoea for this pathogen.