Epidemiologia da esquitossomose mansoni no distrito de Carlos Alves, municipio de São João Nepomuceno, Minas Gerais

Abstract

In Brazil, schistosomiasis is a disease of major socio-economic impact in several states, including Minas Gerais. As most of the surveys carried out in this state have focused on areas of high endemicity, the objective of this study was to investigate the epidemiology of schistosomiasis in the municipality of Sao Joao Nepomuceno, which is considered a low-endemic area of the disease and where neuroschistosomiasis has been reported. A cross-sectional study was conducted from July to December 2011, including all individuals enrolled in the Family Health Program ("Programa de Sande da Familia" - PSF) of the District of Carlos Alves, Sao Joao Nepomuceno, MG. The parasitological survey of the sample population was performed in both urban and rural areas, as follows: one stool sample was collected from each individual and then processed using two techniques - the Kato-Katz (KK) method (two slides), and the formol-ether (FE) method (three slides). 30% of the individuals with negative KK diagnosis were randomly selected and invited to provide a second and a third stool sample. These samples were then examined using the KK method. A questionnaire was also applied to the study population. The malacological survey was carried out in the main hydric collections and the identification of the Biomphalaria species was done. Of the total 688 individuals registered in the PSF, 503 participated in the survey (73.11%). Despite the detection of some other infections, S. mansoni was the parasite most frequently found, with a prevalence of 1.6%. This disease was observed through the KK method only in the first sample of feces. The univariate analysis showed that the prevalence of schistosomiasis was higher in males, with a 17.45 (CI95% = 1.09-304.21) times greater chance of acquiring the disease (p=0.003), and also that the contact with the hydric collection increased by 43.35 (CI95%=2.48-756.81) times the chance of acquiring the disease. B. glabrata was found in the region, but none were infected with S. mansoni. Susceptibility tests have shown that B. glabrata district was highly sensitive to infection with miracidia of S. mansoni. With the techniques of kernel was observed near clusters of the Biomphalaria of infected patients. The occurrence of B. glabrata, as well as of individuals with schistosomiasis increases the need for constant monitoring of this disease in the region.