[A hierarchical model for analysis of socio-economic variables and water contact patterns associated with the hepatosplenic form of schistosomiasis].

A study of factors associated with the hepatosplenic clinical form of schistosomiasis was carried out in an endemic area (Comercinho, Minas Gerais) where prevalence of Schistosoma mansoni infection was 70.4%. Of the 1,408 inhabitants aged two years and over, 1,162 (82.5%) participated in the study. Socio-demographic characteristics and reasons for water contacts of individuals with the hepatosplenic form (n = 73) were compared to those who did not present splenomegaly and eliminated (positive controls; n + 804) or did not eliminate S. mansoni eggs in stools (negative controls; n = 285). Multivariate analysis was performed, considering the existence of colinearity among socio-economic status of the family, running water in the household, and bathing in streams. The hepatosplenic form in children was strongly associated with occupation of the head of the family (manual workers) (OR = 11.4; 95% CI = 1.4 - 91.8), absence of running water in the household (OR = 7.7; 95% CI = 2.6 - 23.1), and bathing in streams (OR and 95% CI 7.6; 2.5-22.9 and 5.7; 1.3-25.5 for frequencies > weekly and <= weekly, respectively); bathing in streams, which implies intense contacts, was a consequence of the first two factors. Our results suggest that running water in the household can decrease morbidity from schistosomiasis because it reduces the need for intense contacts with streams.