The epidemiology of schistosomiasis in Egypt: Minya Governorate

Risk factors, prevalence, and intensity of infection with Schistosoma sp, a nd prevalence and magnitude of morbidity caused by schistosomiasis was asse ssed in a stratified random sample of 16,433 subjects from 2,409 households in 33 rural communities in Minya Governorate, Egypt. The prevalence of S. haematobium ranged from 1.9% to 32.7% among the communities and averaged 8. 9%. The average intensity of infection was a geometric mean egg count (GMEC ) of 8.5 per 10 ml of urine and ranged from 1.6 to 30.9. Prevalence was max imum (18-20%) in those 10-20 years of age and higher in males than in femal es. Intensity of infection followed the same pattern. Infection with S. man soni was present almost exclusively in a single village, confirming spread of this species up the Nile River and its focality in Minya. Risk factors f or S. haematobium infection were an age from 11 to 20; male gender; males b athing in, women washing clothing or utensils in, and children swimming or playing in canals. and a history of, or treatment for, schistosomiasis. Rec ent history of burning micturition was associated with infection in childre n but not in adults, while a history of blood in urine correlated with S. h aematobium infection in both age groups. Reagent strip-detected hematuria a nd proteinuria were highly associated, particularly in children, with S. ha ematobium infection. The presence of hepatomegaly or splenomegaly on physic al examination was not associated with S. haematobium ova in the urine. Hep atomegaly, as measured by ultrasonography in the midclavicular line or the midsternal line, or ultrasonography-detected splenomegaly were not present more frequently in infected subjects than in uninfected subjects. Schistoso ma ova were not detected more frequently in urine of subjects with ultrason ography-detected periportal fibrosis than in the urine from subjects withou t this finding. Ultrasonography-detected urinary bladder wall lesions were detected in only 6 (0.3%) subjects and obstructive uropathy was observed in 54 (2.7%) subjects. The absence of an association between prevalence of ur inary tract morbidity and S. haematobium infections was surprising. Two pos sible explanations are 1) that repeated chemotherapy has reduced the preval ence of urinary tract morbidity and 2) that morbidity was not being detecte d by the ultrasonographic operators.