Social environment, behavior, and schistosomiasis in an urban population in the northeast of Brazil.

The objective of our study was to gain greater insight into the pattern of water contact in relation to schistosomiasis among residents of São Lourenço da Mata, a town in Pernambuco, a state in the Northeast of Brazil. We had two primary objectives: 1) to identify water contact activities that were more likely to produce infection and 2) to examine the socioeconomic factors behind water contact activities. Using a sample of persons 10-25 years old, we carried out a population-based case-control study to investigate the first objective, and a cross-sectional study for the second objective. We found that leisure water contact with flowing water (stream or river) was significantly associated with schistosomiasis. Variables showing a statistically significant association with leisure water contact were economic sector, income, and level of education of the head of the household; type of housing; possessions inside the house; type of domestic water supply; and method of excreta collection. We introduced these variables into a multivariate model to select the ones that were most closely associated with leisure water contact. We used a stepdown procedure, and two variables were retained in the final model: type of domestic water supply and type of housing. We concluded that a decrease in leisure water contact was associated with better socioeconomic conditions. Our results suggest that with the subjects we studied in São Lourenço da Mata there was a socioeconomic determination for leisure water contact. Our data highlight the importance of a broad and integrated approach in studying water contact activities and in implementing behavioral interventions for schistosomiasis prevention and control.