Cryptosporidiosis is a worldwide gastrointestinal disease caused by a protozoan parasite; Cryptosporidium. This study determined the prevalence of Cryptosporidium spp. in fecal samples collected from children, and assessed the association between Cryptosporidium in stool with the patient's age, gender and with seasonality. Fecal samples were collected from 176 children (1-12 years) attending gastrointestinal outpatients' clinics in Aboul-Reesh Cairo University Pediatrics Hospital, Egypt. The samples were examined microscopically and by nested polymerase chain reaction (nPCR) assay targeting Cryptosporidium oocyst wall protein (COWP) gene. The nPCR products were digested by restriction enzyme Rsa I. The obtained fragments were resolved by electrophoresis.PCR was more sensitive than microscopic examination in estimating
Cryptosporidium prevalence. Cryptosporidium oocysts were found in 4.5% (8/176) of samples. Cryptosporidium DNA was in 11.9% (21/176). C. hominis (17 cases or 81%) was the predominant species among symptomatic children, peaking in the summer and a small rise in autumn. This study demonstrated that age, gender and season might shape the prevalence of such protozoa in a given population.