Schistosomiasis mansoni in Bananal (State of Säo Paulo, Brazil). IV. study on the public awareness of its risks in the Palha District

A rather high prevalence of mansoni schistosomiasis has been observed in some localities of Bananal, State of Säo Paulo, during the past decade. The highest prevalence of schistosomiasis was found in the Palha District; it was thus considered adequate for an evaluation of public awareness of the risks involved in acquiring schistosomiasis, a likely outcome of certain behavior patterns. We interviewed 542 district-dwellers. The 5-to-39 age-group constituted 65.5 percent of the whole sample. Concerning the infection, 69.2 percent had hearsay information; 46.1 percent know the infection; 69.6 percent know how it is acquired; 31.5 percent know about the symptoms and 57.1 percent know what can be done to avoid infection; 17.7 percent declared to have acquired the infection at least once in their lifetime; 62.3 percent reported total or partial immersion in collections of water of Bananal, once or twice a week, 53.9 percent of these for bathing or fishing. Although most (91.7 percent) households have treated running water, are connected to the sewage network or have septic tanks, 9 percent of the people interviewed use to defecate on the field. It became clear that the educational messages aimed at this population had not been adequate, having failed to fulfil any expectations. The local people received only piecemeal and subjective information about their problem. The control of schistosomiasis requires an integrated practice, which includes the analysis of macro-determinant factors, such as basic sanitation, habitation, education and health care. In short, we require a multidisciplinary vision of the mechanisms of transmission of the infection, which depends upon adequate planning and well trained personnel, intent on their educational work, to attain satisfactory results

Schistosomiasis mansoni in Bananal (State of Säo Paulo, Brazil). III. Seroepidemiological studies in the Palha District

The Palha district, municipality of Bananal, State of Säo Paulo, Brazil, had 10.3 percent cases of Schistosoma mansoni diagnosed from 1994 to 2000 by coproscopy: about three times the municipality average. The immunofluorescent antibody test was used to assess gut-associated IgM antibody titers of samples from 452 inhabitants. It disclosed 129 (28.5 percent) positive cases. Subjects were classified according to age, sex, birthplace, and period of residence. Titers varied from 8 to 4,096 (geometric mean: 170.2). Seropositives were aged from 6 to 69 years (average: 24.5), 75 percent of them aged 34 or less, predominantly males (78 or 60.5 percent). Of all subjects, 65.7 percent were born and had been living in Bananal since; 24.2 percent came from neighboring municipalities and are residing in Bananal from two months to 89 years (average: 22.7 years). Further Kato-Katz coproscopy from 97 seropositives (geometric mean titer, 619) revealed S. mansoni eggs in 11 subjects (11.3 percent). Serology was deemed useful in screening subjects to be further investigated by coproscopy, considering that blood collection had better acceptance than supplying fecal samples. Higher than average serological titers may indicate new cases in endemic areas. Longitudinal studies associated with epidemiological investigation, including titer evolution are advised, as isolated data are difficult to interpret