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In spite of long-term efforts to eliminate Triatoma infestans (Klug 1834) from Brazil, residual foci still persist in the states of Bahia and Rio Grande do Sul. Data on the genetic variability and structuring of these populations are however lacking. Using nine microsatellite loci, we characterized one residual T. infestans population from Bahia and four from Rio Grande do Sul, and compared them with bugs originally from an older focus in São Paulo; 224 bugs were genotyped. The number of alleles per locus ranged from 5 to 11. Observed and expected heterozygosities per locus ranged, respectively, from 0 to 0.786 and from 0 to 0.764. Significant departures from Hardy-Weinberg equilibrium, mainly due to heterozygote deficits, were detected in all loci and in most populations. Global indices estimated by AMOVA were: Fis was 0.37; Fst was 0.28; and Fit was 0.55; overall indices with p = 0.00 indicated substantial differentiation. Inter-population Fst ranged from 0.118 to 0.562, suggesting strong genetic structuring and little to no gene flow among populations. Intra-population Fis ranged from 0.301 to 0.307. Inbreeding was apparent in all populations except that from Bahia-which might be either linked by gene flow to nearby unsampled populations or part of a relatively large local population. The overall pattern of strong genetic structuring among pyrethroid-susceptible residual T. infestans populations suggests that their persistence is probably due to operational control failures. Detection and elimination of such residual foci is technically feasible and must become a public health priority in Brazil.

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The objective of this study is to report on the colonization of palm trees by Rhodnius neglectus, its invasion in an urban area, in Araçatuba - São Paulo, and the control and surveillance measures that have been put in place. Domiciliary triatomine searches occurred in apartments upon the inhabitants' notification. The collected insects were identified and examined for natural infection and food sources with a precipitin test. To search the palm trees, tarps were used to cover the floor, and a "Munck" truck equipped with a tree-pruning device was utilized. Chemical control was performed with the utilization of a manual compression. In 2009, 81 specimens of Rhodnius neglectus were collected from the domiciles by the population. The precipitin test revealed a presence of human blood in 2.7% of the samples. Entomological studies were carried out in these domiciles and in those located within a radius of 200 meters. The search performed in the palm trees resulted in the capture of 882 specimens of triatomines, negative for tripanosomatids. Mechanical and chemical controls were carried out. New searches conducted in the palm trees in the same year resulted in the capture of six specimens. The mechanical and chemical controls of the palm trees, together with the population's work, proved to be effective, therefore preventing these insects' colonization of the city's domiciles.

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Objetivo: descrever os indicadores da vigilância epidemiológica da doença de Chagas no estado de São Paulo, Brasil. Métodos: foi realizado estudo descritivo dos indicadores entomológicos e epidemiológicos obtidos a partir das atividades desenvolvidas pela Superintendência de Controle de Endemias (Sucen) no período de 2010 a 2012. Resultados: foram realizadas 3.867 notificações de insetos, dos quais 72,0 por cento eram triatomíneos; das 2.785 notificações de triatomíneos recebidas, as pesquisas realizadas nos atendimentos resultaram no encontro do vetor em 746 domicílios; onde foram coletados 15.634 exemplares de triatomíneos, 3,4 por cento deles positivos para Trypanosoma cruzi; a espécie mais coletada foi a Triatoma sordida, predominantemente no peridomicílio; não foi constatada reação positiva para T. cruzi em qualquer das amostras de morador examinadas. Conclusão: apesar do elevado número de notificações de triatomíneos e da constatação de positividade para T. cruzi nesses vetores, não foram encontradas evidências de transmissão da doença de Chagas.

Objective: to describe epidemiological surveillance indicators of Chagas disease in the State of São Paulo, Brazil. Methods: this was a descriptive study of entomological and epidemiological indicators obtained based on activities undertaken by the Endemic Disease Control Department (SUCEN) between 2010-2012. Results: there were 3,867 notifications of insects, of which 72.0 per cent were triatomines. Of the 2,785 triatomine notifications received, the vector was subsequently found in 746 households visited, 15,634 specimens of triatomines were collected, 3.4 per cent were positive for Trypanosoma cruzi. Triatoma sordida was the most collected species and was predominantly found in housebold surroundings. Sample household residents had no positive reaction for T. cruzi. Conclusion: despite the high number of triatomine notifications and T. cruzi positive results in these vectors, no evidence was found of Chagas’ disease transmission.

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The objective of this study is to report on the colonization of palm trees by Rhodnius neglectus, its invasion in an urban area, in Araçatuba - São Paulo, and the control and surveillance measures that have been put in place. Domiciliary triatomine searches occurred in apartments upon the inhabitants' notification. The collected insects were identified and examined for natural infection and food sources with a precipitin test. To search the palm trees, tarps were used to cover the floor, and a “Munck” truck equipped with a tree-pruning device was utilized. Chemical control was performed with the utilization of a manual compression. In 2009, 81 specimens of Rhodnius neglectus were collected from the domiciles by the population. The precipitin test revealed a presence of human blood in 2.7% of the samples. Entomological studies were carried out in these domiciles and in those located within a radius of 200 meters. The search performed in the palm trees resulted in the capture of 882 specimens of triatomines, negative for tripanosomatids. Mechanical and chemical controls were carried out. New searches conducted in the palm trees in the same year resulted in the capture of six specimens. The mechanical and chemical controls of the palm trees, together with the population's work, proved to be effective, therefore preventing these insects' colonization of the city's domiciles.

O objetivo deste trabalho é relatar a colonização de palmeiras por Rhodnius neglectus, sua invasão em área urbana, na cidade de Araçatuba - São Paulo, o controle e as medidas de vigilância instituídas. As pesquisas de triatomíneos nos domicílios ocorreram nos apartamentos quando da notificação pelo morador. Os insetos coletados foram identificados, examinados quanto à infecção natural e teste de precipitina. Na pesquisa das palmeiras foram utilizados lonas para forração do chão e caminhão Munck equipado com moto poda. O controle químico foi realizado com a utilização de compressor manual. No ano de 2009, foram coletados pela população 81 exemplares de Rhodnius neglectus em domicílios. O teste de precipitina acusou presença de sangue humano em 2,7% das amostras. Pesquisas entomológicas foram realizadas nestas edificações e naquelas situadas em um raio de 200 metros onde ocorreram as invasões. A pesquisa realizada nas palmeiras resultou na captura de 882 exemplares de triatomíneos, negativos para tripanosomatídeos. Foi realizado controle mecânico e químico. Novas pesquisas realizadas nas palmeiras avaliadas no mesmo ano resultaram na coleta de seis exemplares. Os controles mecânicos e químicos das palmeiras aliado ao trabalho de participação popular mostraram-se factíveis impedindo a colonização destes insetos nos domicílios da cidade.

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Avaliações das notificações de triatomíneos pela população em áreas de maior dispersão da espécie Panstrongylus megistus apontaram que as mesmas não têm ocorrido, ou acontecem de forma bastante esporádica. Para monitorar a situaçãofoi proposta realização de busca ativa em localidades destas áreas. O critério para a estimativa da amostra das localidades considerou a positividade observada no intra e peridomicílios em imóveis pesquisados no período de 1990 a 1999. Nos anos de 2008 e 2009 foram pesquisadas as unidades domiciliares de 110 localidades, totalizando 4466 domicílios com 20 positivos, perfazendo uma positividade de 0,04% para intradomicílio e 0,4% para o peridomicílio.Coletaram-se 136 exemplares de triatomíneos, 90,4% referentes à espécie Triatoma sordida e 9,6% a Panstrongylus megistus, concentrados noperidomicílio (92,3%). Todos os exemplares examinados foram negativos para Trypanosoma cruzi. Os resultados permitem afirmar que a estratégia de vigilância está sendo conduzida de maneira eficaz, e que, embora se constate a presença de focos de triatomíneos no peridomicílio, não ocorre à instalação de colônias na intradomicílio. Os trabalhos de educação em saúde devem ser intensificados visando manter a população motivada a identificar a presença desses insetos, encaminhar às áreas competentes para a confirmação e controle de eventuais focos de infestação

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The control of the vectors of Chagas' disease in the State of Sao Paulo are discussed, mainly those activities that led to the elimination of Triatoma infestans. Secondary factors that helped the control such as rural exodus are also analyzed. The article shows that since 1965 the control became a campaign with different phases due to the epidemiological situation, the acquired knowledge and the entomological surveillance. After 25 years of work, the elimination of all the focus of Triatoma infestans was finally reached and the campaign was ended. However, due to the possibility of reintroduction of the vector in rural areas by passive transportation besides the presence of secondary vectors (Triatoma sordida and Panstrongylus megistus) in several localities, the vector control activities were not interrupted and the surveillance is continuous.

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O propósito deste estudo foi avaliar a vigilância entomológica da doença de Chagas no Estado de São Paulo, no período de 2007 a 2009. Na ocorrência de notificação de triatomíneo, a pesquisa entomológica tem sido desencadeada pela Sucen, na casa onde se deu o seu encontro e naquelas situadas em seu entorno. Em se constatando sua presença, o controle químico é realizado. No período em questão a Sucenrecebeu 4.709 notificações de triatomíneos, procedentes de 328municípios com coleta de 7.604 exemplares. Os atendimentos a essasnotificações resultaram positivos em 1.058 domicílios, com captura de10.248 triatomíneos. Na pesquisa realizada nas moradias situadas aoredor da casa notificante, em 592 domicílios constatou-se presença de4.573 vetores. As espécies atoma sordida (92,1%) e Panstrongylusmegistus (5,8%) foram as que se destacaram. A taxa de colonização dointradomicílio foi de 13,9%. A positividade para Trypanosoma cruzi foide 1,2%. Reagiram para sangue humano 3,1% dos triatomíneos. A sorologia aplicada a 31 moradores foi positiva em uma amostra. A vigilância em vigor no Estado de São Paulo tem se mostrado eficaz, selecionando previamente casas a serem pesquisadas. Tem ocorridode forma contínua, permitindo monitorar a situação, garantir a sustentabilidade das ações e assegurar a detecção precoce de triatomíneos e o seu controle

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Discute-se o controle dos transmissores da doença de Chagas, no Estado de São Paulo, e as atividades que levaram à eliminação do Triatoma infestans. São destacados os fatores coadjuvantes as ações de controle, particularmente o êxodo rural. A partir de 1965, o combate tomou a forma de uma verdadeira campanha, com fases distintas em função das alterações epidemiológicas, experiência adquirida e pressão dos custos. Após 25 anos de trabalho a campanha foi considerada encerrada, com a eliminação dos focos da espécie do planalto paulista. Porém, em função da possibilidade da reintrodução de Triatoma iinfestans(transporte passivo) e da presença, em diversas localidades, de exemplares de espécies vetoras semidomiciliares (Triatoma sordida e Panstrogylus megistus) as atividades de controle não foram interrompidas. Em consequência, continuam em andamento as ações de vigilância entomológica.

The control of the vectors of Chagas' disease in the State of Sao Paulo are discussed, mainly those activities that led to the elimination of Triatoma infestans. Secondary factors that helped the control such as rural exodus are also analyzed. The article shows that since 1965 the control became a campaign with different phases due to the epidemiological situation, the acquired knowledge and the entomological surveillance. After 25 years of work, the elimination of all the focus of Triatoma infestans was finally reached and the campaign was ended. However, due to the possibility of reintroduction of the vector in rural areas by passive transportation besides the presence of secondary vectors (Triatoma sordida and Panstrongylus megistus) in several localities, the vector control activities were not interrupted and the surveillance is continuous.

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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.

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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 por cento) e os humanos (22,5 por cento) constituíram as principais fontes sanguíneas. Encontrou-se 16 (3,8 por cento) 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 percent) and humans (22.5 percent) were the major blood sources. Sixteen (3.8 percent) 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.

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São apresentados os resultados do controle dos transmissores da doença de Chagas no estado de São Paulo que levaram à eliminação do Triatoma infestans do solo paulista. São descritas as fases pelas quais passou o programa, destacando os fatores, somados às ações de controle, que contribuíram para o seu êxito. Finalmente, são descritas as ações de vigilância dos vetores vigentes no estado, desencadeadas a partir de notificações de insetos, originadas pela população, cujos resultados apontam continuidade e garantem sustentabilidade ao Programa.

We show in this article the results of Chagas? disease vector control program in São Paulo state, Brazil, which resulted in the eradication of Triatoma infestans from the state territory. We describe the various phases of the program, emphasizing the factors which complemented such control actions and contributed to their success. Then, we describe the vector surveillance actions in effect in this state, based on insect notification by the population, which show continuity and warrant the sustainability of the program.

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This study had the aim of assessing the characteristics of triatomine infestation in human dwellings in rural settlement and resettlement areas with regard to the time when infestation began. We analyzed data relating to 48 triatomine surveys carried out in 105 settlement areas and six resettlement areas in the region of Pontal do Paranapanema between January 1984 and June 2005. Among the 16 surveys in settlement areas, seven (43.8%) had positive findings, all of them in communities established eight or more years previously. Among the 32 surveys in resettlement areas, 23 (71.9%) had positive findings, all of them in communities established for periods shorter than eight years. Since the inhabitants of such communities frequently move, the need for constant vigilance to detect any cases of infestation by vector triatomines in new settlements cannot be overemphasized.

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Este estudo teve o objetivo de avaliar, em assentamentos e reassentamentos rurais, tendo em conta seu tempo de formação, características da infestação de habitações por triatomíneos. Analisamos dados referentes a 48 pesquisas de triatomíneos, colhidos durante o período entre janeiro de 1984 e junho de 2005, em 105 assentamentos e seis reassentamentos do Pontal do Paranapanema. Das 16 pesquisas realizadas nos assentamentos, sete (43,8 por cento) resultaram positivas. Todos os assentamentos positivos haviam sido estabelecidos oito ou mais anos antes. Das 32 pesquisas realizadas nos reassentamentos, 23 (71,9 por cento) resultaram positivas; todos os reassentamentos positivos haviam sido estabelecidos menos de oito anos antes. Uma vez que os habitantes dessas comunidades deslocam-se freqüentemente, nunca é demais salientar a necessidade de vigilância constante para detectar possíveis instalações de triatomíneos vetores em novos assentamentos.

This study had the aim of assessing the characteristics of triatomine infestation in human dwellings in rural settlement and resettlement areas with regard to the time when infestation began. We analyzed data relating to 48 triatomine surveys carried out in 105 settlement areas and six resettlement areas in the region of Pontal do Paranapanema between January 1984 and June 2005. Among the 16 surveys in settlement areas, seven (43.8 percent) had positive findings, all of them in communities established eight or more years previously. Among the 32 surveys in resettlement areas, 23 (71.9 percent) had positive findings, all of them in communities established for periods shorter than eight years. Since the inhabitants of such communities frequently move, the need for constant vigilance to detect any cases of infestation by vector triatomines in new settlements cannot be overemphasized.

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Under laboratory conditions, the authors analyzed the survival rate of nymphs, the minimum and maximum duration of each stage, the length of life of the winged forms and oviposition of the females. Two groups of 100 eggs each were monitored. In batch A, the specimens were reared in a single glass receptacle. In batch B, the specimens were kept apart, one by one, and when they reached the winged stage, they formed twenty couples, which made it possible to watch over the oviposition of the females and the length of life of each specimen. The egg eclosion rate was 96%; the proportion still alive at the end of the nymph phase was 69.5% in batch A and 78.4% in batch B. The most frequent length of time observed between oviposition and eclosion of first-stage nymphs was 28 days. The nymph phase lasted four to eight months and the adult phase five months. The mean total oviposition in batch B was 181.6 eggs per female.

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Os autores analisaram em condições de laboratório, a taxa de sobrevida das ninfas, duração mínima e máxima de cada estádio, tempo de vida das formas adultas e postura das fêmeas. Foram acompanhados dois grupos de 100 ovos. Lote A, exemplares criados em um único cristalizador. Lote B os exemplares foram mantidos isolados um a um e ao atingir a fase alada formaram 20 casais, possibilitando o controle da postura das fêmeas e o tempo de vida de cada exemplar. O percentual de eclosão dos ovos foi de 96 por cento; a taxa de vida no final da fase ninfal foi de 69,5 por cento no Lote A e de 78,4 por cento no Lote B. A maior freqüência observada no tempo decorrido entre postura e eclosão da ninfa do 1° estádio foi de 28 dias. O tempo de permanência na fase de ninfa foi de 4 a 8 meses e de 5 meses na fase adulta. A postura total (média) no Lote B foi de 181,6 ovos por fêmea.

Under laboratory conditions, the authors analyzed the survival rate of nymphs, the minimum and maximum duration of each stage, the length of life of the winged forms and oviposition of the females. Two groups of 100 eggs each were monitored. In batch A, the specimens were reared in a single glass receptacle. In batch B, the specimens were kept apart, one by one, and when they reached the winged stage, they formed twenty couples, which made it possible to watch over the oviposition of the females and the length of life of each specimen. The egg eclosion rate was 96 percent; the proportion still alive at the end of the nymph phase was 69. 5 percent in batch A and 78. 4 percent in batch B. The most frequent length of time observed between oviposition and eclosion of first-stage nymphs was 28 days. The nymph phase lasted four to eight months and the adult phase five months. The mean total oviposition in batch B was 181. 6 eggs per female.

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The objective of this study was to analyze the surveillance of Chagas' disease in São Paulo State through notifications registered from 1990 to 1999. The information originated when notification of triatomines was announced by inhabitants and the established control program was followed. 20,563 triatomine notifications were received, showing a decrease over the years, with more accentuated decreases in the area of greatest frequency of Panstrongylus megistus. Each notification corresponded to an average of 1.3 examples of captured triatomines (median = 1), predominantly in the intradomicile area, while during attendance, the mean number of collected insects was 3.6 (median = 2), mostly present in the peridomicile area. The notification distribution permitted the demarcation of three different areas in the state: area 1, comprising the areas of São José do Rio Preto, Araçatuba and part of Presidente Prudente; area 2, São Vicente and Sorocaba; area 3, municipalities located to the northeast of the Campinas region. Analysis showed that entomological surveillance through triatomine notification, despite the fall in the same, has not detected intradomiciliary colonies associated with Trypanosoma cruzi which could give rise to vectorial transmission of Chagas' disease.

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O objetivo deste estudo foi analisar a vigilância da doença de Chagas no Estado de São Paulo, através da notificação, na década de 1990. As informações foram originadas quando da notificação de triatomíneos pelos moradores e seguiram o normatizado pelo Programa de Controle. Foram recebidas 20.563 notificações de triatomíneos com queda ao longo dos anos, sendo esta mais acentuada na região que compreende a área de maior freqüência de encontro de Panstrongylus megistus. Cada notificação correspondeu em média a 1,3 exemplares de triatomíneos capturados (mediana=1), predominantemente no intradomicílio, enquanto nos atendimentos a média de insetos coletados foi de 3,6 (mediana=2), presentes na maioria no peridomicílio. A distribuição das notificações permitiu demarcar três áreas distintas do Estado: área 1- compreendida pelas regiões de São José do Rio Preto, Araçatuba e parte de Presidente Prudente; área 2- São Vicente e Sorocaba; área 3- municípios situados a nordeste da região de Campinas. A análise mostrou que a vigilância entomológica através da notificação de triatomíneos, a despeito da queda das mesmas, não tem detectado colônias intradomiciliares associadas a infecção por Trypanosoma cruzi que possam dar origem à transmissão vetorial da doença de Chagas humana.

The objective of this study was to analyze the surveillance of Chagas' disease in São Paulo State through notifications registered from 1990 to 1999. The information originated when notification of triatomines was announced by inhabitants and the established control program was followed. 20,563 triatomine notifications were received, showing a decrease over the years, with more accentuated decreases in the area of greatest frequency of Panstrongylus megistus. Each notification corresponded to an average of 1.3 examples of captured triatomines (median = 1), predominantly in the intradomicile area, while during attendance, the mean number of collected insects was 3.6 (median = 2), mostly present in the peridomicile area. The notification distribution permitted the demarcation of three different areas in the state: area 1, comprising the areas of São José do Rio Preto, Araçatuba and part of Presidente Prudente; area 2, São Vicente and Sorocaba; area 3, municipalities located to the northeast of the Campinas region. Analysis showed that entomological surveillance through triatomine notification, despite the fall in the same, has not detected intradomiciliary colonies associated with Trypanosoma cruzi which could give rise to vectorial transmission of Chagas' disease.

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