Jr. Coura et al., CROSS-SECTIONAL AND EVOLUTIVE STUDIES OF SCHISTOSOMIASIS-MANSONI IN UNTREATED AND MASS TREATED ENDEMIC AREAS IN THE SOUTHEAST AND NORTHEASTOF BRAZIL, Memorias do Instituto Oswaldo Cruz, 87, 1992, pp. 175-182
Cross-sectional and evolutive studies on schistosomiasis mansoni were
carried out before and after mass treatment in the endemic areas of Ca
pitao Andrade and Padre Paraiso, state of Minas Gerais, Riachuelo, sta
te of Sergipe, Alhandra, state of Paraiba, and Alianca, Alegre and Cor
oata, lowland of the state of Maranhao, Brazil, in the last eighteen y
ears. The studies included clinical and fecal examination by the Kato-
Katz quantitative technique, skin test for Schistosoma mansoni infecti
on, evaluation of man-water contact and other epidemiological investig
ations such as infection rate and dynamic of the snail population. Res
ults showed: (1) Higher prevalence of S. mansoni infection, greater eg
g load elimination and higher and earlier morbidity of the chronic for
ms of the disease in the southeast areas of Capitao Andrade and Padre
Paraiso; (2) The incidence of hepatosplenic form is higher in some fam
ily clusters, in whites and mulattos in all the endemic areas but deve
lop earlier in the southeast; (3) The prevalence and morbity of schist
osomiasis are decreasing both in the mass treated northeast and in the
untreated southeast areas; (4) The mass treatment reduces rapidily th
e prevalence of the infection and the morbidity of the disease but can
not control it because of the frequent reinfections due to the intens
ity of man-water contact.