RESUMO
During the last twenty years, several adults of Triatoma tibiamaculata infected with Trypanosoma cruzi have been spontaneously caught by inhabitants, inside their houses in the new habitational district of Pitua¿u of Salvador, Bahia. In this communication the authors call attention to the necessity of studies about the possibility of occurrence of new human cases of Chagas disease, to clarify the obscure origin of some positive blood donors in Salvador.
Assuntos
Doença de Chagas/transmissão , Habitação , Insetos Vetores/parasitologia , Triatoma/parasitologia , Trypanosoma cruzi/isolamento & purificação , Animais , Brasil/epidemiologia , Doença de Chagas/epidemiologia , Doenças Endêmicas , Feminino , Humanos , Fatores de Risco , Triatominae/parasitologiaRESUMO
From July to September of 1998, 152 fleas were collected from 18 specimens of the fox Cerdocyon thous captured in the visceral leishmaniasis endemic area of Jacobina, State of Bahia, Brazil. The fleas were identified as: 136 Rhopalopsyllus lutzi lutzi, 11 Pulex irritans, 2 Ctenocephalides canis, 1 Ctenocephalides felis felis and 2 Xenopsylla cheopis.
Assuntos
Reservatórios de Doenças/veterinária , Raposas/parasitologia , Insetos Vetores/classificação , Leishmaniose Visceral/transmissão , Sifonápteros/classificação , Animais , Brasil , Feminino , Masculino , Estações do AnoRESUMO
The laboratory and field observations summarized in this paper on visceral leishmaniasis ecology in the State of Bahia, Brazil are based on the author's observations over the past 35 years in a number of state's foci, public health records and literature citations. The disease is endemic with epidemic outbreaks occurring every ten years and its geographical distribution is expanding rapidly in the last years. Leishmania chagasi is the main ethiologic agent of the visceral leishmaniasis but Le. amazonensis s. lato was the only leishmania isolated by other authors from some visceral leishmaniasis human cases in the state. Lutzomyia longipalpis (with one or two spots on tergites III and IV and two sized different populations) was epidemiologically incriminated as the main vector. It was found naturally infected with promastigotes, and it was infected with four species of leishmanias in the laboratory. Although the experimental transmission of Le. amazonensis by the bite of Lu. longipalpis to hamsters was performed, the author was not successful in transmitting Le. chagasi in the same way. The dog is the most important domestic source for infection of the vector, however it is not a primary reservoir. The opossum Didelphis albiventris was found naturally infected with Le. chagasi but its role as reservoir is unknown. Foxes and rodents were not found infected with leishmanias in Bahia.
Assuntos
Doenças Endêmicas , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/parasitologia , Animais , Brasil , Ecologia , Humanos , Leishmania infantum/fisiologia , Leishmania mexicana/fisiologia , Psychodidae/parasitologia , Estudos RetrospectivosRESUMO
Preliminary data of a project about the ecology of the Phlebotominae (sandflies) in a tegumentary leishmaniasis area of coconut plantation in the south of the State of Bahia, Brazil are presented. There are 60 dwellings far of one another, where existed 31 dogs and 229 inhabitants. Among them 41.5% were Montenegro positive; 37.5% from these had scars of healed ulcers and 8.8% had active ulcers. 53% of the house had dogs from which 22% were seropositive; from the 7 dogs with ulcers only 3 were seropositive. 14% of the inspected house harboured sandflies inside them. During two years of observations 72 sentinels hamsters were maintened at houses of patients with leishmaniasis ulcers, but they did not get the infection. During two years of observation, monthly collectings of sandflies were made inside house, chicken pen, curral, tree trunks and open field around a house with a patient with leishmaniasis. The following results were already obtained about the vectors: 5,614 specimens were identified as belonging to fourteen different species of sandflies. Among them Lutzomyia whitmani (92%) and Lutzomyia intermedia (4.8%) were the most abundant species. They are very anthropophilic and can be found inside houses and at peridomestic sites. Probably they are the principal vectors of the disease at domestic places. The other twelve species were less frequent and more found at sylvatic places in inspite they also bite the man. Generally the biting activity of most of the species of the area begins at 5 p.m. in the dusk and reaches its peak at 0 hour a.m., when begins declining until disapear at 7 a.m. L. whitmani was similarly collected with the same density in all lunar phases while L. intermedia was more abundant during the new moon phase. Most of the hundreds sandflies collected during the second year of observations, remains preserved in liquid nitrogen, watching for the adjustment of PCR molecular techniques to be processed for determination of the vector natural infection rates with leishmanias. Final results on all the project will be published as soon as the examination of such material has been processed.
Assuntos
Ecologia , Insetos Vetores , Leishmaniose Cutânea/transmissão , Phlebotomus , Animais , Brasil , Cães , Humanos , Leishmaniose Cutânea/parasitologia , Densidade DemográficaRESUMO
Durante os anos de 1982 a 1986, a investigaçäo sobre mamíferos comensais e silvestres, da periferia da cidade de Jacobina, Bahia, mostrou, ao lado do escasso número de exemplares, uma reduzida variedade específica dessa fauna. Capturou-se apenas 11 espécies, entre as quais, predominou o Didelphis a albiventris, que abrangeu 44% dos 213 espécimes capturados Didelphis albiventris, que abrangeu 44% dos 213 espécimes captura capturados. Entre os 193 com exames já concluídos, 84 eram exemplares de D. albiventris e 2 estavam infectados pela Leishmania donovani senso lato, 1 por L. mexicana amazonensis, 1 por L. braziliensis, subespécie e 3 por Trypanosoma cruzi. Também foram observadas formas suspeitas de serem amastigotas de leismanics, nos esfregaços de órgäos de 3 exemplares de Dasyprocta aguti, 1 Cercomys cunicularius-e 1 Oryzomys eliurus. O restante dos exemplares, inclusive 14 de Lycalopex vetulus, estava negativo para flagelados. Apesar de reforçado por outros indicadores epidemiológicos, como a predominância específica, a freqüência domiciliar, a atratividade para a vetora Lutzomya longipalpis, e a concomitância com casos humanos nos mesmos locais, o índice de 2,3% de infecçäo natural do Didelphis albiventris, näo autoriza a conclusäo definitiva de ser o marupial o mais importante reservatório natural da leishmaniose visceral em Jacobina
Assuntos
Animais , Reservatórios de Doenças , Leishmaniose Visceral , Animais Selvagens , Brasil , Leishmania braziliensis , Leishmania donovani , Leishmania mexicana , Gambás , ZoonosesRESUMO
Foi usado um teste imunoenzimático competitivo para investigar a presença de anticorpos anticomponente 5 nos soros de sariguês, cäes, coelhos e ratos infectados com o Trypanosoma cruzi. Neste teste, foi utilizado um anticorpo monoclonal contra o antígeno 5 que é específico do T. cruzi. Também foram testados os soros de 51 pacientes venezuelanos com doença de Chagas. Apesar desses anticorpos näo serem detectados nos soros de cäes, ratos e sariguês infectados com o T. cruzi, alguns soros de coelhos infectados apresentaram resultados positivos porém em níveis próximos aos do limite de positividade do teste. Esses achados surgerem que a resposta imune em animais naturalmente ou experimentalmente infectados com o T. cruzi é diferente daquela que é observada na doença de Chagas humana