EPIDEMIOLOGY OF SCHISTOSOMIASIS-MANSONI IN 3 ENDEMIC COMMUNITIES IN NORTHEAST ETHIOPIA - BASE-LINE CHARACTERISTICS BEFORE ENDOD BASED INTERVENTION

As pan of a Pre-intervention baseline data collection the epidemiologi cal characteristics of:schistosomiasis mansoni were studied in 3 endem ic communities (Kemise, Harbu and Bati towns) in;northeast Ethiopia in April and May 1994. The objective was to generate data based on which post-intervention differences tin changes), if any, in transmission l evel could partly be explained for the 3 towns. After calculating the sample size required for each town 132, 75, 158 households were select ed by systematic random sampling from Kemise Harbu and Bati, respectiv ely and all members of the selected households stool was examined by t he Kato's thick smear method. Eighty eight and 85% of the houses harbo ured one or more-cases of Schistosoma mansoni in Kemise and in Bati, r espectively, all members of the households being positive in 27% in Ke mise and in 28% in Bati. The overall prevalences were 59%, 33% and 51% in Kemise, Harbu aad Bati respectively, with the corresponding geomet ric mean egg counts (epg) of 240,123 and 195 for positives and 26,5 an d 15 for the whole populations. All ages combined, there were no signi ficant differences due to sex both in prevalence and intensity of infe ction. By age, children in the 10-14 years age group were most affecte d (p=0.007), their prevalences reaching 86%, 52% and 66% in Remise Har bu and Bati, respectively and their corresponding geometric mean epg b eing 377, 157 and 401, respectively.; Heavy infection (> 100 epg) reac hed 42%, 32% and 16% in Kemise, Bati and Harbu, respectively, reaching an average of 55% among the 10-14 years of age. The implications of t he epidemiological findings and the possible use of the household appr oach for rapid assessment of schistosomiasis magnitude in an area are discussed.