Clinical-epidemiological study of schistosomiasis mansoni in school children of Ilha, Arcos County, Minas Gerais, Brazil, 1983

Abstract

A schistosomiasis mansoni clinical-epidemiological study was carried out among school children (6-14 years old) of the Ilha community, Minas Gerais. Stool examination, using the KATO-KATZ method, and clinical examination were performed on 86.7 and 85.4%, respectively, of the population studied. The signs and symptoms presented by the patients as well as their contacts with untreated water were investigated. A socio-economic survey was carried out in the community through household interviews. The index of infection by the Schistosoma mansoni was 32.7%, low egg counts were predominant (89.0% of the patients eliminated less than 500 eggs/gram of feces) and the index of splenomegaly was 7.7%. The positive patients (presenting S. mansoni eggs in the stools) were compared with the negative ones .(without eggs in the stools and presenting a negative intradermal reaction). The S. mansoni infection was significantly higher among the rural workers, among those who lived in poor housing conditions and among those patients the head of whose family was illiterate. Increased risk factors were found to be: a) the contact with untreated water used for agriculture (OR = 18.08); b) the occurrence of daily contact with untreated water (OR = 13.82) and c) the contact with untreated water for fishing, swimming and/or playing (OR = 7.75 and 5.51 respectively). The authors consider the hypothesis that the schistosomiasis transmission in this area does not occur in household surroundings but in the nearby lagoons and agricultural areas instead (probably in irrigated rice plantations).