ABSTRACT
No combate à doença de Chagas no Brasil, foi utilizado como primeira medida o controle químico, erradicando o Triatoma infestans, o mais importante vetor, tal combate vem favorecendo o aparecimento de vetores secundários, como Triatoma sordida and Panstrongylus megistus, espécies que podem eventualmente ser encontradas no domicílio, como os triatomíneos provenientes de Bernardino de Campos e Sete Barras por nós examinados que foram encontrados no domicílio e positivos para o T. cruzi, sugerindo que, apesar da doença de Chagas estar controlada no Estado de São Paulo, existe a necessidade de aprimorar os conhecimentos sobre o comportamento destes vetores para que mudanças nas medidas de controle sejam introduzidas.
As a first measure of Chagas' disease control in Brazil with chemical elimination of the most important vector of the disease, Triatoma infestans was removed. Attention is now being paid to Triatoma sordida and Panstrongylus megistus. That species can eventually be found inside houses, as happened with the specimens we examined from Bernardino de Campos and Sete Barras, all of them infected by Trypanosoma cruzi. These data suggest that a better knowledge about the behavior that species is needed to introduce changes in the control measures.
Subject(s)
Animals , Female , Male , Mice , Insect Vectors/parasitology , Panstrongylus/parasitology , Brazil , Chagas Disease/parasitology , Ecosystem , Mice, Inbred BALB C , Nymph/parasitology , Parasitemia/parasitology , Trypanosoma cruzi/isolation & purification , Trypanosoma cruzi/pathogenicityABSTRACT
1. Trypanosoma cruzi epimastigote forms are very rapidly removed from the circulation of normal and C5-deficient mice. Depletion of C3 by cobra venom factor results in a significant delay in parasite clearance. 2. During parasite clearance there is a significant decrease in the number of circulating platelets and parasite clearance is considerably delayed in thrombocytopenic animals. 3. In vitro incubation of epimastigote forms with normal mouse serum leads to the formation of parasite clumps provided that platelets are present. Innactivation of factor B or depletion of C3 prevents this phenomenon. 4. When epimastigotes are incubated with normal mouse serum they absorb one or more factors required for their aggregation with platelets. 5. It is suggested that in mice T. cruzi epimastigote forms are removed from circulation by the alternative pathway of complement activation and that both C3 and platelets are required for parasite clearance