ABSTRACT
Background The reintroduction of sylvatic yellow fever in the state of São Paulo after about six decades was confirmed in the Northwestern region in 2000, where in 2008 there also occurred an important epizootic. The purpose of this study was to investigate the feeding habits of culicids potentially involved in the sylvatic transmission of the virus in this region.Methods Specimens were collected in 24 forested localities at ground level with hand nets and mouth aspirators. Collections were made quarterly between October 2006 and July 2008 during daylight hours. Blood-meal identification was carried out in mosquitoes of the tribes Aedini, Mansoniini and Sabethini. The biotin/avidin sandwich ELISA was employed to determine six source types: bird, bovine, equine, rat, human and monkey.Results A total of 24,879 females of the three tribes were obtained, 245 (0.98%) of which were engorged. The presence of three different blood sources per engorged female was the predominant situation, and included 35.10% of the total of samples processed. Samples with two or four different sources were represented by 25.31% and 25.71%, of the specimens, respectively, while just 9.39% had only one type and 1.22%, five different sources. Aedes scapularis, Ae. serratus(Group),Psorophora albigenu and Ps. ferox were the most abundant species and accounted for about 95% of the engorged specimens. Of the principal vector species,Haemagogus janthinomys/capricorniiwas found with bird, bovine and primate blood. These sources were predominant and alternated top ranking as the most frequent source according to the mosquito species and collection site. In general, primate blood was the most prevalent source.Conclusions The human population of the region visits this ecotone frequently, which indicates the need for the periodical assessment of vaccination coverage against yellow fever. The frequency of non-human primate blood source in mosquito species that show minor vector importance in yellow fever virus transmission deserves attention. The eclectic feeding habits and some aspects of the interactions between potential vectors and reservoirs of yellow fever may be associated with the habitat fragmentation characteristic of the region. We recommend that further studies on the capacity and vector competence be performed on secondary vectors in extra-Amazonian region.(AU)
Subject(s)
Animals , Yellow Fever , Yellow fever virus , Enzyme-Linked Immunosorbent Assay , Ecosystem , DipteraABSTRACT
AbstractBackground The reintroduction of sylvatic yellow fever in the state of São Paulo after about six decades was confirmed in the Northwestern region in 2000, where in 2008 there also occurred an important epizootic. The purpose of this study was to investigate the feeding habits of culicids potentially involved in the sylvatic transmission of the virus in this region.Methods Specimens were collected in 24 forested localities at ground level with hand nets and mouth aspirators. Collections were made quarterly between October 2006 and July 2008 during daylight hours. Blood-meal identification was carried out in mosquitoes of the tribes Aedini, Mansoniini and Sabethini. The biotin/avidin sandwich ELISA was employed to determine six source types: bird, bovine, equine, rat, human and monkey.Results A total of 24,879 females of the three tribes were obtained, 245 (0.98%) of which were engorged. The presence of three different blood sources per engorged female was the predominant situation, and included 35.10% of the total of samples processed. Samples with two or four different sources were represented by 25.31% and 25.71%, of the specimens, respectively, while just 9.39% had only one type and 1.22%, five different sources. Aedes scapularis, Ae. serratus(Group),Psorophora albigenu and Ps. ferox were the most abundant species and accounted for about 95% of the engorged specimens. Of the principal vector species,Haemagogus janthinomys/capricorniiwas found with bird, bovine and primate blood. These sources were predominant and alternated top ranking as the most frequent source according to the mosquito species and collection site. In general, primate blood was the most prevalent source.Conclusions The human population of the region visits this ecotone frequently, which indicates the need for the periodical assessment of vaccination coverage against yellow fever. The frequency of non-human primate blood source in mosquito species that show minor vector importance in yellow fever virus transmission deserves attention. The eclectic feeding habits and some aspects of the interactions between potential vectors and reservoirs of yellow fever may be associated with the habitat fragmentation characteristic of the region. We recommend that further studies on the capacity and vector competence be performed on secondary vectors in extra-Amazonian region.
Subject(s)
Animals , Feeding Behavior , Culicidae , Yellow Fever , Insect VectorsABSTRACT
O objetivo deste estudo foi realizar vistoria em imóveis para identificar condições facilitadoras para a instalação de colônias de triatomíneos. Selecionaram-se localidades caracterizadas pela persistência de infestação durante toda a década de 1990. Realizaram-se pesquisas de triatomíneos em todos os domicílios, confeccionando-se ?croquis? do peridomicílio com descrição dos anexos e distância entre cada anexo e o domicílio. Foram vistoriados os imóveis em quatro momentos diferentes. Ensinou-se aos moradores o modo correto de manutenção e limpeza do intradomicílio e peridomicílio. Identificaram-se 72 moradores, com mediana de idade de 41,5 anos. Composto por 65 domicílios, foram identificados 27,6 porcento positivos para triatomíneos, com coleta de 355 exemplares, representados principalmente por T. sordida 97,3 porcento. Os tipos de anexos mais expressivos foram árvores com ninhos 21,8 porcento e galinheiros 13,8 porcento. A distância média observada dos anexos em relação à moradia foi de 15,7 metros. Houve acréscimo de 8,6 porcento de anexos no período. Não se encontrou relação entre o fato de o morador ser proprietário do imóvel e a infestação por triatomíneos. A instrumentalização da população para práticas educativas adequadas de saúde pode atuar como moderadora do impacto da infestação por vetores da doença de Chagas, o que não foi observado neste estudo, refletindo na qualidade de vida e proteção de novas gerações.
The objective of this study was to perform inspections in properties to identify facilitating conditions for the installation of triatomine colonies. Places characterized by infestation persistence during the whole 1990 were selected. Triatomines researches were conducted in all households, producing sketches of the peridomicile area with description of the annexes and the distance between each annex and the household. The properties were inspected in four different moments. The correct way of maintaining and cleaning of the intradomicile and peridomicile area was taught to the inhabitants. They identified 72 inhabitants with a mean age of 41.5. Of the 65 studied residences 27.6 porcento tested positive for triatomine with collection of 355 samples, the majority being T. sordida 97.3 porcent. The more expressive types of annex were trees with nests 21.8 porcent and hen houses 13.8 porcento. The average distance observed of the annex in relation to the dwellings was 15.7 meters. There was an increase of 8.6 porcento of annexes in the period. There was no relationship found between the fact that the inhabitant is the owner of the property and the infestation by triatomines. Providing the population with the tools for the suitable educational practices of health may serve as a mitigator of the impact of the infestation by vectors of Chagas disease, a fact that was not observed in this study and that reflects in the life quality and protection of new generations.
El objetivo de este estudio fue realizar una vistoria en imuebles para identificar condiciones facilitadoras para la instalación de colonias de triatomíneos. Se seleccionaron localidades caracterizadas por la persistencia de infestación durante toda la década del 1990. Se realizaron investigaciones de triatomíneos en todos los domicilios, confeccionándose ?croquis? del peridomicilio con descripción de los anexos y distancia entre cada anexo y el domicílio. Fueron vistoriados los imuebles en cuatro momentos diferentes. Se enseñó a los habitantes el modo correcto de mantención y limpieza del intradomicilio y peridomicilio. Se identificaron 72 habitantes, con edad media de 41,5 años. Compuesto por 65 domicilios, fueron identificados27,6 por ciento positivos para triatomíneos, con colecta de 355 ejemplares, representados, principalmente por T. sordida 97,3 por ciento. Los tipos de anexos más expresivos fueron árboles con nidos 21,8 por ciento y gallineros 13,8 por ciento. La distancia media observada de los anexos en relación a la moradia fue de 15,7 metros. Hubo incremento de 8,6 por ciento de anexos en el período. No se encontró relación entre el hecho del habitante ser propietario del imueble y la infestación por triatomíneos. La instrumentalización de la población para prácticas educativas adecuadas de salud puede actuar como moderadora del impacto de la infestación por vetores de la enfermedad de Chagas, lo que no fue observado en este estudio, reflejando en la calidad de vida y protección de lãs nuevas geraciones.
Subject(s)
Humans , Triatominae , Chagas Disease/transmission , Insect VectorsABSTRACT
Avaliou-se a diversidade de mosquitos em diferentes habitats antes e depois da formação do reservatório de Igarapava no Rio Grande, Cerrado do Sudeste do Brasil, com objetivo de verificar alteração nessas populaçäes de mosquitos. Quatro habitats foram selecionados como sítios de coleta: a) peridomicílio rural, b) pastagem, c) veredas e d) mata ciliar. Realizaram-se coletas bimestrais com isca humana e armadilha de Shannon, incluindo períodos de atividade culicídea diurna, crepuscular vespertina e noturna. Os resultados do Indice de Shannon para os potenciais vetores nos diferentes habitats foram comparados pelo teste t de Student. As abundâncias sazonais de Aedes scapularis, Anopheles darlingi e Anopheles albitarsis s.l., foram descritas com a média móvel e comparadas com o teste c2. Houve alteração nas freqüências dos mosquitos nos habitats, com exceção das veredas, que estavam afastadas 13 km da área de influência do reservatório. A modificação nas abundâncias sazonais dos potenciais vetores sugere o incremento de criadouros após a formação do reservatório. Indices de diversidade são ferramentas úteis para monitorar populaçäes de mosquitos vetores em ambientes cujas mudanças drásticas podem alterar ciclos de transmissão de doenças transmitidas por vetores.
Subject(s)
Humans , Animals , Aedes , Biodiversity , Insect Vectors , Anopheles , Seasons , Brazil , Population Density , MalariaABSTRACT
After the realization of control research that had in view the transmission of dengue virus, we started to monitor two kinds of entomological vigilance, Breteau Index and ovitrap. We intended to evaluate the necessary time elapsed before Aedes sp mosquitoes were again detected at the urban area of Catanduva s town (SP). The ovitraps showed positiveness for the Aedes aegypti two months after the control research, while the Breteau Index became positive only at the fourth month after the end of the referred research.