ABSTRACT
This study was conducted on 187 patients with acute diarrhea and 20 controls attending the out patient clinics of Abbaseya Fever Hospital and Kasr El Aini Hospital. They included both sexes and different age groups. This study has demonstrated the high frequency of protozoal infections [68/187] in acute diarrhea in different age groups. Giardiasis represented 13 percent and amoebiasis 8 percent, with even a higher frequency in non-diarrhoeic cases [35 percent]. As regards cryptosporidiosis it was detected in 4 percent of diarrheic patients and all cases were below 2 years of age with the exception of one patient aged 60 years. Blastocytis hominis was detected in a high frequency [16 percent], only 7 of them had pure infection with no other enteric pathogens. Dientamaeba fragilis show a low frequency of only 1 percent. The details of age predilection and clinical presentations of each of these parasites were also studied