INTRODUÇÃO: A pesquisa da fonte alimentar dos triatomíneos auxilia no conhecimento sobre a biologia destes insetos, inclusive para inferir-se a importância dos mesmos como transmissores do Trypanosoma cruzi ao homem. MÉTODOS: O presente estudo objetivou registrar, através da reação de precipitina, a fonte alimentar de triatomíneos provenientes de 54 municípios da região centro-oeste de Minas Gerais, assim como a infecção natural destes para flagelados semelhantes ao Trypanosoma cruzi. RESULTADOS: De julho de 2003 até março de 2007, foram avaliados 416 insetos, todos da espécie Panstrongylus megistus. Somando-se as ocorrências, as aves (70%) e os humanos (22,5%) constituíram as principais fontes sanguíneas. Encontrou-se 16 (3,8%) insetos positivos para flagelados semelhantes ao Trypanosoma cruzi sendo que oito realizaram hematofagia no homem. CONCLUSÕES: Os resultados demonstram necessidade de acentuar a vigilância entomológica na região, visto que foi detectada a possibilidade de ocorrência de novos casos da doença de Chagas através da transmissão vetorial.

INTRODUCTION: Investigation of the food source of triatomines helps in understanding the biology of these insects, and also helps to infer their importance in transmitting Trypanosoma cruzi to humans. METHODS: The present study aimed to use the precipitin reaction to record the food source of triatomines from 54 municipalities in the central-western region of the State of Minas Gerais, as well as their natural infection by flagellates similar to Trypanosoma cruzi. RESULTS: From July 2003 to March 2007, 416 insects were evaluated, all from the species Panstrongylus megistus. Among all these occurrences, birds (70%) and humans (22.5%) were the major blood sources. Sixteen (3.8%) of the insects were found to be positive for flagellates similar to Trypanosoma cruzi, and eight performed hematophagia on humans. CONCLUSIONS: The results show the need to increase the entomological surveillance in this region, given that the possibility of new cases of Chagas disease occurring through vector transmission was detected.

Canine American visceral leishmaniasis and American cutaneous leishmaniasis (ACL) cases have been recorded in Espírito Santo do Pinhal. The aim of this study was to gather knowledge of the sand fly community and its population ecology within the municipality. Captures were made weekly over a period of 15 months in the urban, periurban and rural areas of the municipality, using automatic light traps. A total of 5,562 sand flies were collected, comprising 17 species. The most abundant species were Nyssomyia whitmani and Pintomyia pessoai in the rural area, Lutzomyia longipalpis and Ny. whitmani in the periurban area and Lu. longipalpis in the urban area. The highest species richness and greatest index species diversity were found in the rural area. The similarity index showed that urban and periurban areas were most alike. Lu. longipalpis was found in great numbers during both dry and humid periods. The presence of dogs infected with Leishmania infantum chagasi in the urban area indicates a high risk for the establishment of the disease in the region. A high abundance of Ny. whitmani and Pi. pessoai in the rural and periurban areas indicates the possibility of new cases of ACL occurring in and spreading to the periurban area of Espírito Santo do Pinhal.

Relata-se os resultados de uma investigação sobre a possibilidade da existência de memória em flebotomíneos em área endêmica de leishmaniose tegumentar americana, no Estado do Paraná. Capturaram-se flebotomíneos no Recanto Marista, Doutor Camargo, Estado do Paraná, Brasil, com armadilhas de Falcão, de 15/11/2007 a 26/11/2007, em dois galinheiros (G1 e G2). Foram capturados 2.080 flebotomíneos (1.000 em G1 e 1.080 em G2), que foram marcados e soltos. Nyssomyia neivai foi a espécie mais (90,5%) freqüente. Do total solto, recapturaram-se 168 (8%) flebotomíneos e a recaptura no G2 foi significativa. Os resultados evidenciam que é possível a existência de memória espacial, olfativa e/ou a fidelidade ao hospedeiro e que isto orientem os flebotomíneos no reconhecimento dos locais onde há disponibilidade de fontes de sangue.

The results from an investigation on the possibility that sandflies in an endemic area for American cutaneous leishmaniasis, in the state of Paraná, may have memory are reported. Sandflies were caught in Recanto Marista, Doutor Camargo, State of Paraná, Brazil, using Falcão traps in two chicken sheds (G1 and G2), between November 15 and 26, 2007. A total of 2,080 sandflies were caught (1,000 in G1 and 1,080 in G2) and these were marked and released. Nyssomyia neivai was the most (90.5%) frequent species. Out of the total released, 168 sandflies (8%) were recaptured and the recapture rate in G2 was significant. The results show that it is possible that spatial or olfactory memory and/or host loyalty exists, and that this will guide the sandflies in recognizing the places where sources of blood are available.

The aim of this work is to present aspects related to the ecology of Rhodnius nasutus Stål, 1859 in palms from Chapada do Araripe in Ceará, Brazil. The following five species of palms were investigated: babaçu (Attalea speciosa), buriti (Mauritia flexuosa), carnaúba (Copernicia prunifera), catolé (Syagrus oleracea) and macaúba-barriguda (Acrocomia intumescens). Fifth palms were dissected (10 specimens for each species). The overall infestation index was 86%, with a total of 521 triatomines collected. The Trypanosoma cruzi Chagas, 1909 Index was 16.8% and two insects presented mixed infection with Trypanosoma rangeli Tejera, 1920. A precipitin test showed that R. nasutus from palms of Chapada do Araripe are associated with opossum and bird although other possible bloodmeals were observed. Our results showing a high index of infestation of the palms as well as T. cruzi infection, the association of R. nasutus with the most diverse species of palms and proximity of these palms to houses demonstrate the importance of this area for sylvatic T. cruzi transmission and suggest the need for epidemiological surveillance in the region of the Chapada do Araripe.

Foram capturados triatomíneos rupestres em seis localidades do município de Quaraí-RS, com o intuito de verificar o índice de infecção por Trypanosomatidae, bem como o animal reservatório. A captura ocorreu no ambiente silvestre, sendo coletados 453 exemplares, os quais foram identificados e separados por estádio ninfal. Coletaram-se 421 (92,9%) exemplares de Triatoma rubrovaria, 26 (5,7%) de Triatoma circummaculata e 6 (1,3%) de Panstrongylus tupynambai. Dentre as três espécies coletadas, somente Triatoma rubrovaria mostrou-se positivo para Trypanosomatidae, num total de 13 (4,2%) exemplares. Após a inoculação em camundongos e meio de cultura LIT, isolaram-se cinco cepas de Trypanosoma cruzi. Dos triatomíneos infectados com Trypanosomatidae, 4 (30,8%) tiveram a reação de precipitina não reagente para os anti-soros testados, 4 (30,8%) positivos para anti-soro de roedor, 4 (30,8%) para anti-soro de cabra e 1 (7,7%) para anti-soro de porco e humano.

Rupestrian triatomines were captured in six Quaraí city localities, RS, to verify the level of Trypanosomatidae infection, as well as the animal reservoir. The capture occurred in a wild environment and 453 samples were collected, which were identified and separated by nymphal instar. 421 (92.9%) samples of Triatoma rubrovaria, 26 (5.7%) of Triatoma circummaculata and 6 (1.3%) of Panstrongylus tupynambai were collected. Only 13 samples (4.2%) of Triatoma rubrovaria presented Trypanosomatidae infection. After mice and LIT culture inoculation, five strains of Trypanosoma cruzi were isolated. Of these triatomines, 4 (30.8%) displayed no reagent precipitin for the antiserum tested, 4 (30.8%) were positive for rodent antiserum, 4 (30.8%) were positive for goat antiserum and 1 (7.7%) were positive for human and pig antiserum.

The dispersal pattern of the sand fly Lutzomyia neivai was studied through mark-release-recapture experiments in an American cutaneous leishmaniasis endemic rural area in Southeastern Brazil. Over 6500 specimens were marked with fluorescent powder and released in forest edge and peridomicile habitats from August to November 1999, February and April 2000. Recapture attempts were made using Shannon and CDC traps up to eight successive nights after releases. A total of 493 (7.58%) specimens were recaptured. The number of recaptured males and females of L. neivai in CDC traps was not affected by the distance between the trap and the release points. Approximately 90% of males and females recaptured in CDC traps were caught up to 70 m from the release points. The maximum female flight range recorded was 128 m. The average flight range per day was less than 60 m for males and females. Of the flies released in forest edge, approximately 16% of the recaptured females were caught in Shannon traps in the peridomicile habitat. The results indicate that the movements of L. neivai are spatially focal and the possibility of dispersion from forest to peridomicile habitat may be an important way of contracting leishmaniasis in dwellings.

A região do litoral norte do Estado de São Paulo registrou 14, 30 e 104 casos de leishmaniose tegumentar americana nos anos de 1993, 1994 e 1995 respectivamente. Com objetivo de caracterizar a fauna e a distribuição sazonal e horária das espécies de flebotomíneos foram realizadas coletas quinzenais de formas adultas durante o período de dezembro de 1995 a novembro de 1996, utilizando-se armadilhas luminosas do tipo CDC, no interior da residência, no peridomicílio e na mata durante 12 horas a partir do crepúsculo vespertino. No peridomicílio foi utilizada, durante 6 horas também a partir do crepúsculo vespertino, armadilha de Shannon instalada a 100 metros da casa. A cada 3 meses esta armadilha foi utilizada durante 12 horas. Foram observadas flutuações das densidades populacionais, bem como as ocorrências intra e extradomiciliar das espécies predominantes. Lutzomyia intermedia foi a espécie mais abundante nas diferentes armadilhas utilizadas e nos ambientes investigados.

Fourteen, 30 and 104 cases of American tegumentary leishmaniasis were recorded respectively, in 1993, 1994 and 1995, in the coast region of São Paulo State. Aiming to characterize the fauna and seasonal and hourly distributions of the phlebotominic species, adult specimens were captured fortnightly between November/95 and December/96. CDC light traps were used as of dusk intradomiciliarly, peridomiciliarly and in the forest for 12 hours. From the same moment on but only during 6 hours Shannon traps were set in the peridomicile 100 meters from the house. Quarterly this trap was used for 12 hours. The population density fluctuation as well as the occurrence of intra and extradomiciliarly predominant species were observed. In the different traps used and environments investigated Lutzomyia intermedia was the most abundant species.

The identification of breeding sites of sand flies is of great epidemiological interest. A soil emergence trap for investigating potential sand fly breeding sites is described. The trap was tested in two rural areas in the Mogi Guaçu River Valley where the American cutaneous leishmaniasis is an endemic disease. Seventy-three sand fly individuals of three species, Lutzomyia intermedia s. l., L. whitmani and L. pessoai, were collected on the forest floor and peridomicile.

INTRODUÇÃO: Estudo descritivo, entomológico e soroepidemiológico da infecção chagásica em área de ocupação recente da periferia de Cochabamba, Bolívia: Avaroa/Primer de Mayo, onde o nível socioeconômico da população é baixo e não foram instituídas medidas de controle. MÉTODOS: Por meio da reação de imunofluorescência indireta (RIFI), de anticorpos IgG e IgM anti-Trypanosoma cruzi em sangue capilar absorvido em papel-filtro, foram pesquisadas 128 pessoas (73 femininas e 55 masculinas) selecionadas por amostragem sistemática dentre 3.000 habitantes. Registraram-se idade, sexo, naturalidade, ocupação, tempo de moradia e características de construção das casas. RESULTADOS: Verificou-se que 12,5% (16/128) foram sororreagentes: 15,1% (11/73) do sexo feminino e 9,1% (5/55) masculino. O tempo médio de moradia foi de 6,1 anos para toda a amostra da população e de 7,4 anos para os sororreagentes. Predominaram construções de adobe (76,7%), teto de zinco (86,7%) e piso de terra (53,4%). Observaram-se gretas nas paredes de 80,0% das casas (n=30). Capturaram-se 148 exemplares de triatomíneos: 147 de Triatoma infestans, 104 (70.7%) intradomiciliares, e 1 de T. sordida, peridomiciliar. Os índices de infestação e de densidade por casa visitada foram, respectivamente, 53,3 e 493,0. A identificação dos hospedeiros dos triatomíneos (reações de precipitina) foi: aves, 67,5%; humanos, 27,8%; roedores, 11,9%; cães, 8,7%; e gatos, 1,6%. Os adultos e ninfas de T. infestans infectados por tripanossomas foram: 21 (14,3%), dos quais 18 (85,7%) intradomiciliares. CONCLUSÕES: Na área periférica de Cochabamba estudada foram encontrados todos os elementos da cadeia de transmissão vetorial: pessoas e vetores infectados e cobaios criados no interior das casas. A proximidade de Cochabamba, onde as transfusões de sangue são freqüentes, representa um risco adicional de transmissão. É necessária a pronta instituição de medidas profiláticas e trabalho educativo sobre as vias de transmissão da doença de Chagas, inclusive transfusional e congênita.

INTRODUCTION: A descriptive, entomological and seroepidemiological study on Chagas disease was conducted in a place of recent occupation on the outskirts of Cochabamba, Bolivia: Avaroa/Primer de Mayo (population:3,000), where the socio-economic level is low and no control measures have been made available. METHODS: The immunofluorescent antibody test (IFAT) was used for IgG and IgM anti-Trypanosoma cruzi antibodies in filter paper bloodspot eluates from 128 subjects (73 females, 55 males) selected by systematic sampling. Concerning each subject age, gender, birthplace, occupation, duration of residence and building materials used in their houses were recorded. Vectors were captured both in domestic and peridomestic environments. RESULTS: Seropositive, 12.5% (16/128): females, 15.1% (11/73); males, 9.1% (5/55). Average time of residence: 6.1 years for the whole population sample and 7.4 years for the seropositive subjects. Most houses had adobe walls (76.7% , n= 30), galvanized iron rooves (86.7%) and earthen floors (53.4%) 80% of the walls had crevices. One hundred forty seven specimens of Triatoma infestans were captured, of which 104 (70.7%) were domestic, and 1 peridomestic Triatoma sordida. Precipitin host identification: birds, 67.5%; humans, 27.8%; rodents, 11.9%; dogs, 8.7%; cats, 1.6%. House infestation and density indices were 53.3 and 493.0 respectively. We found 21 (14.3%) specimens of T. infestans infected with trypanosomes, 18 (85.7%) of which in domestic environments. DISCUSSION: The elements for the vector transmission of Chagas disease are present in Avaroa/Primer de Mayo and the ancient custom of keeping guinea pigs indoors adds to the risk of human infection. In neighboring Cochabamba, due to substandard quality control, contaminated blood transfusions are not infrequent, which further aggravates the spread of Chagas disease. Prompt action to check the transmission of this infection, involving additionally the congenital and transfusional modes of acquisition, is required.

INTRODUÇÃO: Estudo descritivo, entomológico e soroepidemiológico da infecção chagásica em área de ocupação recente da periferia de Cochabamba, Bolívia: Avaroa/Primer de Mayo, onde o nível socioeconômico da população é baixo e não foram instituídas medidas de controle. MÉTODOS: Por meio da reação de imunofluorescência indireta (RIFI), de anticorpos IgG e IgM anti-Trypanosoma cruzi em sangue capilar absorvido em papel-filtro, foram pesquisadas 128 pessoas (73 femininas e 55 masculinas) selecionadas por amostragem sistemática dentre 3.000 habitantes. Registraram-se idade, sexo, naturalidade, ocupação, tempo de moradia e características de construção das casas. RESULTADOS: Verificou-se que 12,5% (16/128) foram sororreagentes: 15,1% (11/73) do sexo feminino e 9,1% (5/55) masculino. O tempo médio de moradia foi de 6,1 anos para toda a amostra da população e de 7,4 anos para os sororreagentes. Predominaram construções de adobe (76,7%), teto de zinco (86,7%) e piso de terra (53,4%). Observaram-se gretas nas paredes de 80,0% das casas (n=30). Capturaram-se 148 exemplares de triatomíneos: 147 de Triatoma infestans, 104 (70.7%) intradomiciliares, e 1 de T. sordida, peridomiciliar. Os índices de infestação e de densidade por casa visitada foram, respectivamente, 53,3 e 493,0. A identificação dos hospedeiros dos triatomíneos (reações de precipitina) foi: aves, 67,5%; humanos, 27,8%; roedores, 11,9%; cães, 8,7%; e gatos, 1,6%. Os adultos e ninfas de T. infestans infectados por tripanossomas foram: 21 (14,3%), dos quais 18 (85,7%) intradomiciliares. CONCLUSÕES: Na área periférica de Cochabamba estudada foram encontrados todos os elementos da cadeia de transmissão vetorial: pessoas e vetores infectados e cobaios criados no interior das casas. A proximidade de Cochabamba, onde as transfusões de sangue são freqüentes, representa um risco adicional de transmissão. É necessária a pronta instituição de medidas profiláticas e trabalho educativo sobre as vias de transmissão da doença de Chagas, inclusive transfusional e congênita.

INTRODUCTION: A descriptive, entomological and seroepidemiological study on Chagas disease was conducted in a place of recent occupation on the outskirts of Cochabamba, Bolivia: Avaroa/Primer de Mayo (population:3,000), where the socio-economic level is low and no control measures have been made available. METHODS: The immunofluorescent antibody test (IFAT) was used for IgG and IgM anti-Trypanosoma cruzi antibodies in filter paper bloodspot eluates from 128 subjects (73 females, 55 males) selected by systematic sampling. Concerning each subject age, gender, birthplace, occupation, duration of residence and building materials used in their houses were recorded. Vectors were captured both in domestic and peridomestic environments. RESULTS: Seropositive, 12.5% (16/128): females, 15.1% (11/73); males, 9.1% (5/55). Average time of residence: 6.1 years for the whole population sample and 7.4 years for the seropositive subjects. Most houses had adobe walls (76.7% , n= 30), galvanized iron rooves (86.7%) and earthen floors (53.4%) 80% of the walls had crevices. One hundred forty seven specimens of Triatoma infestans were captured, of which 104 (70.7%) were domestic, and 1 peridomestic Triatoma sordida. Precipitin host identification: birds, 67.5%; humans, 27.8%; rodents, 11.9%; dogs, 8.7%; cats, 1.6%. House infestation and density indices were 53.3 and 493.0 respectively. We found 21 (14.3%) specimens of T. infestans infected with trypanosomes, 18 (85.7%) of which in domestic environments. DISCUSSION: The elements for the vector transmission of Chagas disease are present in Avaroa/Primer de Mayo and the ancient custom of keeping guinea pigs indoors adds to the risk of human infection. In neighboring Cochabamba, due to substandard quality control, contaminated blood transfusions are not infrequent, which further aggravates the spread of Chagas disease. Prompt action to check the transmission of this infection, involving additionally the congenital and transfusional modes of acquisition, is required.

In the Epidemiological Surveillance Program in the county of Bambuí, Minas Gerais, between August 1986 and December 1988, 154 Panstrongylus megistus were captured by the local population in both peridomicile and intradomicile environments. Fifteen (9.8%) of the P. megistus harboured Trypanosoma cruzi. Preciptin tests showed that the most frequent triatomine blood meal sources were birds, but other sources were dogs, men and cats. The isoenzyme characterization of 13 T. cruzi strains showed that six belonged to zymodeme Z1, corresponding to the wild parasites, and seven belonged to zymodeme Z2, corresponding to parasites isolated from chronic chagasic patients (domestic cycle). As P. megistus were found to be naturally infected by parasites from both cycles, they are cleary able to transmit T. cruzi from the wild cycle to the domestic cycle. Furthermore the capacity of P. megistus in colonizing houses was observed in one residence, vacant for several years, in wich 153 triatomines were captured. The data show the possibility of P. megistus reintroducing transmission of Chaga's disease in the county if Epidemiological Surveillance is interrupted.