Environmental perception and schistosomiasis: a study of rural children in Brazil

The human-water relationship is highly important in humanity's survival and full of symbolic values. For schistosomiasis infection to occur, it is necessary for humans to contact water bodies harboring snails from several different species. However, studies of human-water contact behavior have not focused on the cognitive aspects of schistosomiasis transmission. This study tested the hypothesis that differ- ences in perception of aspects of the environment (e.g., bodies of water) that are known to be important in schistosomiasis transmission will be associated with different levels of prevalence of this disease in a population of children. A sample of 523 children (5-16 years old) living in seven rural communities in Northeast Brazil was studied. Each child was exposed to two color slides and the response was considered "positive" when the child mentioned water among the features he or she described. The findings demon- strated a significant association between those responding positively to the perception of the environmental characteristics in question and the presence of Schistosoma mansoni infection. Among those infected, 56.2% responded positively to the test; among those not infected, only 34.5% gave positive response.