A combined strategy to improve the control of Schistosoma mansoni in areas of low prevalence in Brazil.

ABSTRACT

Results of stool examinations for infections with Schistosoma mansoni among schoolchildren, living in a village of Minas Gerais State, Brazil, were used as an indicator to identify schistosomiasis-positive individuals within the entire population. This new approach is based on dividing the community into schoolchildren, members of households of schistosomiasis-positive and -negative schoolchildren, and members of households without schoolchildren. Each subgroup was evaluated comparing different sampling efforts with the predetermined "gold standard" to find the best relationship between detection rate and sampling effort. Consequently these results were combined, and a proposal for a new strategy, valid for an entire community, was elaborated. This alternative approach during the screening process permits to treat a similar proportion of positives as detected with 6 Kato-Katz slides of 3 stool samples, with 3-fold reduced sampling effort, enhancing the efficiency of schistosomiasis control programs in low-endemic areas.