Do regional variations in prevalence of cryptosporidiosis occur? The central Ohio experience.

We screened 2,780 consecutive stool specimens submitted for routine ova and parasite examination to assess the prevalence of cryptosporidiosis in a pediatric patient population in central Ohio. The stools were prepared by formalin-ethyl acetate concentration followed by cold Kinyoun acid-fast stain of the sediment. In addition, 912 consecutive intestinal biopsies were monitored for the presence of the parasite. Cryptosporidium oocysts were found in only 0.3 per cent of stool specimens (seven specimens from three patients) and in none of the intestinal biopsies. Due to this low prevalence of cryptosporidiosis, we conclude that routine screening of stool specimens for Cryptosporidium sp. is unnecessary in our patient population. Screening should be targeted to immune compromised patients and patients with persistent diarrhea and no apparent etiology. Our study also supports the concept that there are geographic variations in the prevalence of cryptosporidiosis.