Additional data on the epidemiology of chagas disease in the municipality of Caxias, Rio de Janeiro state, Brazil

Abstract

An area believed to be an autochthonous focus for Chagas' disease was investigated in the municipality of Caxias, Rio de Janeiro State. The study included search for domestic triatomine bugs, serological test (IFT and CFT) in persons in whose house infested bugs were discovered, detailed clinicai examination and xenodiagnosis test of ali serologicall/ yy positive persons, and xenodiagnosis test on dogs from households in which infected triatomine bugs have been found. Only in one of the locatities (Piranema) domestic Triatoma infestans have been discovered. some of which were infected with T. cruzi. A small number of persons (mostly children) had a positive serologicál test for Chagas’ disease, but in all of them the infection was clinically asymptomatic. From two dogs, belonging to a household in which serologically positive children and infected T. infestans were discovered, T. cruzi was isolated by xenodiagnosis. The importunt epidemiological information obtained from this investigation was the discovery of domestic adaptation of T. infestans in an area with dense population .and with very low social and sanitary conditions, in a locality considered as non-endemic for the infection.O presente trabalho baseia-se no estudo de um foco autóctone da doença de Chagas no município de Caxias, no Estado do Rio de Janeiro. O estudo incluiu a pesquisa de triatomíneos nos domicílios das localidades de Piranema, Amapá e Capivarí, inquérito sorológico pelas reações de imuno-fluorescência e fixação do complemento para doença de Chagas na população dessas localidades e xenodiagnóstico dos casos com sorologia positiva e em animais domésticos das residências onde foram encontrados triatomíneos infectados. De 115 casas pesquisadas na localidade de Piranema, 15 (13,0%) estavam infestadas com Triatoma infestans. Nas demais localidades não foram encontrados triatomíneos. De um total de 1936 T. infestans capturados, 146 estavam infectados com Trypanosoma cruzi. Do ponto de vista epidemiológico é importante assinalar a adaptação do Triatoma infestans ao domicílio humano numa área com grande densidade de população na baixada fluminense, em município próximo ao litoral do Estado do Rio de Janeiro.