Environmental intervention as a tool for control of schistosomiasis: suggestions from a field study in Northeast Brazil

Abstract

The present survey from the State of Alagoas (Brazil) emphasized, once again, the importance of peridomestic or neighbourhood foci in the transmission of schistosomiasis mansoni. Although the study area consisted of a compact and densely populated urban community (Bairro Frio, União dos Palmares county), prevalence as well as the distribution of high egg counts was quite patchy, exhibiting a spatial pattern correlated with the distribution of ditches and other small-sized collections of surface water. Despite the availability of satisfactory water supply in most households, as well as the absence of any major body of water capable of furthering transmission, egg counts in Bairro Frio exceeded any other in our previous experience. Morbidity, however, appeared to be insignificant, a trend which has been observed over the last decade in several other highly endemic areas. It appears clear to the authors that the control of transmission requires investment in environmental intervention and that this proposal, far from being utopic, can be furthered by quite modest means and through the participation of community or neighbourhood groups.

Avaliação de medidas de controle da esquistossomose mansoni no Município de Sabará, Minas Gerais, Brasil, 1980-2007

“…Fatores sócio-econômicos e sócio-demográficos também são determinantes na transmissão da doença, sendo imprescindível levá-los em consideração antes de se decidir por qualquer medida. Vários pesquisadores 7,8,9,10 observaram a associação de tais fatores com a ocorrência da esquistossomose. Estudos realizados em áreas urbanas e rurais de diversas regiões endêmicas do país encontraram as mesmas dificuldades em relacionar fatores sócio-econômicos com risco de infecção por Schistosoma mansoni por causa da homogeneidade das condições sociais e sanitárias das populações em estudo.…”

Schistosomiasis control based on repeated chemotherapy in a rural village of the sugar-cane zone in Northeast Brazil

“…Since continuing cycles of bi-annual treatment would be unfeasible, the best strategy here might be to combine targeted chemotherapy with other measures, such as small-scale environmental interventions (Kloetzel et al 1994, Pieri 1995 and focal mollusciciding (Sturrock 1995).…”