SCHISTOSOMA-MANSONI IN THE NILE DELTA, EGYPT - A LARGE-SCALE EPIDEMIOLOGIC-STUDY IN KAFR-EL-SHEIKH GOVERNORATE

This is an early descriptive report of the 'Epidemiology 123' project in Egypt which makes use of large probability sampling methods, These results focus on Schistosoma mansoni infection in the northern Nile De lta Governorate of Kafr El Sheikh, A probability sample of 18,777 pers ons, representing the rural population of the entire Governorate, was drawn, The sample was designed not to exclude villages based on locati on or presences of health care facilities and to include representatio n of the smaller ezbas or hamlets, The objective was to obtain detaile d estimates on age and sex specific patterns of S. mansoni infection, and to provide a baseline for prospective studies, Stool specimens wer e examined by the Kato method, The estimated prevalence of S. mansoni infection in the rural population was 39.3% (SE +/- 3.3) in 44 village s and ezbas after weighing for the effects of the sample design, The e stimated geometric mean egg count per grant stool (GMEC) was 72.9 (SE +/- 7.3). Prevalence and GMEC varied considerably by village and ezba, with ezbas having a significantly higher prevalence, Villages and ezb a specific prevalence was strongly associated with GMEC (r(2) = 0.61, p<0.001), The prevalence of S. mansoni infection increased by age to 5 5.4% (SE +/- 3.2) at age 16, without significant change in the adult a ges, There was no gender difference until age six, after which males w ere consistently higher until middle age, when the differences converg ed, The age and sex specific pattern of GMEC varied widely, however, w hen the GMEC data were collapsed into five year age groups, GMEC peake d at 81.5 (SE +/- 12.1) epg in the 10 to 14 year age group. These esti mates provide the basis for evaluating control measures for reducing p revalence, intensity of infection, and transmission.