IMPACT OF POPULATION-BASED SELECTIVE CHEMOTHERAPY ON PREVALENCE AND INTENSITY OF SCHISTOSOMA-MANSONI INFECTIONS IN THE NILE DELTA - KAFR-EL-SHEIKH

The impact of selective treatment with praziquantel (40 mg/kg) on Schi stosoma mansoni prevalence and intensity of infection in two annual fo llow up examinations was measured, The target population was the entir e rural area of the northern Nile Delta Governorate, Kafr El Sheikh, f rom which a probability sample was drawn, The sample included 44 villa ges and hamlets (ezba), Baseline prevalence was determined by the Exam ination of stool by two Kato slides and all infected persons treated a nd reexamined one year later, Those found infected in the second round were treated and examined again one year later, The prevalence and ge ometric mean egg count declined across all ages in each follow-up (Pre valence: 39.3% (SE +/- 3.3), 28.4% (SE +/- 2.6), and 22.4% (SE +/- 2.3 ), respectively; and GMEC: 72.9 (SE +/- 7.3), 52.5 (SE +/- 4.5), and 4 1.9 (SE +/- 2.4), respectively), Reduction in prevalence varied consid erably by village and ezba and was strongly related to the proportion of the village or ezba population that was infected and treated (r(2) = 0.29), This latter observation provides a rationale for the maximum application of chemotherapy in the endemic Nile Delta community.