Cryptosporidium infections: a laboratory survey.

Between Oct. 1, 1983, and June 30, 1985, Cryptosporidium oocysts were identified in stool specimens from 74 patients who presented with gastrointestinal symptoms to their physicians. Questionnaires prepared to determine travel history, symptoms, duration of illness and epidemiologic characteristics of the infection were completed for 67 (90%) of the patients by their physicians; the information on the other 7 patients was obtained from the requisitions accompanying the specimens. Of the 67, 35 (52%) had recently been to Mexico. The infection was likely transmitted through contaminated water, food and, possibly, milk. The infections in patients who had not travelled were thought to be due to contact with infected pets or farm animals or with infected children attending daycare centres. Diarrhea, vomiting, fever and nausea usually lasted for 1 to 2 weeks, except in those with immune deficiency, in whom the symptoms persisted for up to 6 months. The condition was diagnosed by identification of oocysts in stool specimens that underwent formalin-ether sedimentation and modified cold Kinyoun staining.