The epidemiology of schistosomiasis in Egypt: Assiut Governorate

In the Assiut, Egypt Epidemiology 1, 2, 3 investigation, a sample of 14,204 persons in 10 villages, 31 ezbas (satellite communities), and 2,286 househ olds was drawn from a rural population of 1,598,607. Parasitologic examinat ion of urine and stool were made for Schistosoma haematobium and S. mansoni , and physical and ultrasound examinations were made on a 20% subsample. Th e overall estimated prevalence of S. haematobium was 5.2 +/- 0.5 (+/- SE). This varied considerably by village and ezba, ranging from 1.5% to 20.9%, w ith ezbas having a slightly higher overall prevalence than villages. The ov erall estimated geometric mean egg count was 6.6 +/- 0.5 eggs per 10 mi of urine and was consistently low throughout the communities. Infection with S . haematobium was associated with age (peak prevalence of 10.6 +/- 1.5% in 15-19-year-old age group) males, children playing in the canals, a history of blood in the urine, and reagent strip positivity for hematuria and prote inuria. The prevalence of either hepatomegaly or splenomegaly detected by p hysical examination was low (4.0% and 1.5%, respectively). The prevalence o f hepatomegaly determined by ultrasonography was substantially higher, 24.1 %. The prevalence of periportal fibrosis (PPF) was 12.0%, but grade II or I II PPF was present in less than 1%. Ultrasonography-determined hepatomegaly , in both the midclavicular line and the midsternal line, increased by age to more than 30%. Periportal fibrosis was more common in the age groups in which infection rates were the highest. At the village and ezba level of an alysis, the prevalence of hepatomegaly, splenomegaly, and PPF tended to be higher in communities having the highest prevalence of infection with S. ha ematobium.