Occurrence of Cryptosporidium oocysts in fecal samples submitted for routine microbiological examination.

During a 7-month period, 2,252 fecal samples submitted for routine microbiological examination from 1,621 patients were screened for Cryptosporidium oocysts by the auramine staining method with Kinyoun acid-fast stain as the confirmatory stain. Cryptosporidium oocysts were detected in fecal samples from 19 (1.2%) patients, 18 of whom had gastroenteritis. Diarrheic stools from 14 of these 18 patients were negative for the usual enteropathogens but contained the oocysts in moderate to large numbers. Although Cryptosporidium oocysts were found in patients of all ages, they occurred slightly more frequently in infants and children than in the rest. Cryptosporidium species was one of the common enteropathogens identified in fecal samples submitted for routine parasitological examination during the period of the survey and was second only to Giardia species in terms of frequency. Considering cryptosporidiosis in the differential diagnosis of gastroenteritis in immunocompetent persons and including a search for Cryptosporidium oocysts in routine parasitological examinations of fecal samples appear warranted.