Chagas disease in the Amazon Region

The risk that Chagas disease becomes established as a major endemic threat in Amazonia (the world's largest tropical biome, today inhabited by over 30 million people) relates to a complex set of interacting biological and social determinants. These include intense immigration from endemic areas (possibly introducing parasites and vectors), extensive landscape transformation with uncontrolled deforestation, and the great diversity of wild Trypanosoma cruzi reservoir hosts and vectors (25 species in nine genera), which maintain intense sylvatic transmission cycles. Invasion of houses by adventitious vectors (with infection rates > 60 percent) is common, and focal adaptation of native triatomines to artificial structures has been reported. Both acute (~ 500) and chronic cases of autochthonous human Chagas disease have been documented beyond doubt in the region. Continuous, low-intensity transmission seems to occur throughout the Amazon, and generates a hypoendemic pattern with seropositivity rates of ~ 1-3 percent. Discrete foci also exist in which transmission is more intense (e.g., in localized outbreaks probably linked to oral transmission) and prevalence rates higher. Early detection-treatment of acute cases is crucial for avoiding further dispersion of endemic transmission of Chagas disease in Amazonia, and will require the involvement of malaria control and primary health care systems. Comprehensive eco-epidemiological research, including prevalence surveys or the characterization of transmission dynamics in different ecological settings, is still needed. The International Initiative for Chagas Disesae Surveillance and Prevention in the Amazon provides the framework for building up the political and scientific cooperation networks required to confront the challenge of preventing Chagas disease in Amazonia.

Epidemiologia da doença de Chagas: aspectos históricos, sociais e morbidade em duas áreas endemicas de Minas Gerais, Brasil / Epidemiology of Chagas disease: historical and social aspects and morbidity in two endemic areas of Minas Gerais

Analise epidemiologica sobre a organizacao espacial, realizada nos municipios de Berilo e Coronel Murta, no Vale do Jequitinhonha, nordeste de Minas Gerais, com um estudo historico, socio-economico e de relacoes de trabalho em tres periodos, com a distribuicao dos vetores de morbidade da doenca de Chagas, avaliada atraves de um inquerito sorologico, clinico, eletrocardiografico e radiologico pareados.