Epidemiologia da esquistossomose em três municípios da microrregião de Juiz de Fora, Minas Gerais

Abstract

The epidemiology of schistosomiasis has undergone significant transformation in recent decades in Brazil. In the state of Minas Gerais there has been a decline in morbi-mortality, along with advances in diagnosis and treatment, but these have not been sufficient to prevent the geographic spread of the endemic. Clinically, schistosomiasis can appear in acute and chronic hepatosplenic forms, the latter more frequent in areas of high endemicity. Another incapacitating and underreported form, schistosomotic myeloradiculopathy, deserves attention because of its potential severity and the fact it can also occur in areas with low endemicity, since it does not depend on the infection’s intensity. A cross-sectional study was carried out to determine the prevalence and intensity of schistosomiasis in the resident population and the distribution of intermediate hosts in three municipalities in the Juiz de Fora micro-region. The sample was drawn from families listed in the Basic Health Service Information System (SIAB), from which 850 families were investigated through coproparasitological tests by the Kato-Katz technique and the application of a structured questionnaire. This study was groundbreaking in verifying an average schistosomiasis mansoni prevalence of 2.4% in the municipalities of Piau (2%), Goianá (2.1%) and Coronel Pacheco (3.1%). The transmissibility characteristics in the region were evaluated and described. The infected individuals were predominantly young adults. Only 10% of the school-age subjects were positive and there were no indicators of households with sick adults. The results permitted identifying the pattern of aggregation, revealing the individuals with greater parasite loads. The three species of snail carriers were identified in the areas studied: B. glabrata, B. straminea, and B. tenagophila. Therefore, in situations of low endemicity, in regions with population under 5,000 people and covered by family preventive health programs, the study of the prevalence of schistosomiasis based on sample data from households listed in the SIAB is appropriate to identify the groups of greater transmission. The infected individuals were spatially referenced together with the host snails, indicating the probable foci of greatest transmission in the municipalities studied.