Schistosomiasis mansoni in three localities of western lowland of the state of Maranhão before and after mass treatments

Abstract

A cross-sectional study for schistosomiasis was carried out in the localities of Aliança, Alegre and Coroatá (districts of Cururupu, São Bento and São João Batista, respectively) in the lowland of the state of Maranhão, after respectively 13, 11 and 4 mass treatments with oxamniquine in the period of ten years (1977-1987). The study included clinical and quantitative fecal examination, skin test for Schistosoma mansoni infection, evaluation of man-water contact of the total population (829 persons) in the three localities and other epidemiological investigations such as infection rate and dynamics of the snail population. After 13 mass treatments in Aliança, the prevalence of S. mansoni infection was reduced from 57.9% to 7.4%. In Coroatá with 11 mass treatments the prevalence fell from 69.2% to 12.8% and in Alegre, with only 4 mass treatments there was practically no reduction in prevalence: 22.9% to 21%. After mass treatments the type II hepatointestinal clinical form was 10.8% in Aliança, 17.9% in Alegre and 18% in Coroatá. The hepatosplenic (type III) form was not seen in Aliança and Coroatá but unexplanably it was 7.6% in Alegre. There was no correlation between the egg load elimination and the clinical forms.

Schistosomiasis mansoni in Bananal (State of São Paulo, Brazil): II. Intermediate hosts

“…In recent years, Dias et al (1989) andMarçal Jr. et al (1991), when examining snails from the municipality of Pedro de Toledo, in the valley of River Ribeira de Iguape, obtained similar results. The percentages of shedding snails were comparable to those recorded by Barbosa and Costa (1961), Baptista et al (1989), Cutrim and Coura (1992) and Coura Filho et al (1996) Brazil (1998Brazil ( -2001.…”