Factors involved in Schistosoma mansoni infection in rural areas of northeast Brazil

RESUMO

Two contiguous villages in Tracunhaem country (State of Pernambuco) endemic for schistosomiasis, were studied Itapinassu (138 inhabitants) and Sao Joaquim (91 inhabitants). Agriculture predominates in the former region while ceramics is the main activitiy in the latter. Although no statistical difference was found regarding prevalence, severe infection (<400 epg) predominated in Itapinassu, probably related to the kind of occupation. No association was found between parasite burden and severity of disease, in spite of the high infection rates for Schistosoma mansoni in both communities (aprox. 60 per cent). Typical epidemiological features of schistosomiasis such as age-realted prevalences and intensities of infection (high in children, low in adults) were also mutual characteristics. Nutritional status determined through anthropometric evaluation was carried out by measuring specific anthropometric indicators. A deficit of energy intake, as well as vitamin A and riboflavin deficiencies were detected. The prevalence of moderate or severe undernutrition in patients under 18 years old was 21.9 per cent in Itapinassu and 24.1 per cent in Sao Joaquim. In this group as association was found between prevalence of schistosomiasis and chronic undernutrition. Similarly, for patients over 18 years old the prevalence of undernutrition was higher than 20 per cent. However, in this case no association between nutritional status and either prevalence of schistosomiasis or parasite burden could be detected. The two communities had not been treated for eight years.