Impact of dams and irrigation schemes in Anopheline (Diptera: Culicidae) bionomics and malaria epidemiology

Irrigation schemes and dams have posed a great concern on public health systems of several countries, mainly in the tropics. The focus of the present review is to elucidate the different ways how these human interventions may have an effect on population dynamics of anopheline mosquitoes and hence, how local malaria transmission patterns may be changed. We discuss different studies within the three main tropical and sub-tropical regions (namely Africa, Asia and the Pacific and the Americas). Factors such as pre-human impact malaria epidemiological patterns, control measures, demographic movements, human behaviour and local Anopheles bionomics would determine if the implementation of an irrigation scheme or a dam will have negative effects on human health. Some examples of successful implementation of control measures in such settings are presented. The use of Geographic Information System as a powerful tool to assist on the study and control of malaria in these scenarios is also highlighted.Intervenções humanas como projetos de irrigação e usinas hidrelétricas, tem se transformado em graves problemas de saúde em muitos países, especialmente naqueles localizados nos trópicos. No presente artigo discutimos os efeitos que essas intervenções causam a dinâmica populacional dos anofelinos e nos padrões de transmissão de malaria. Foram revisados estudos feitos nas três principais regiões geográficas dos trópicos e sub-trópicos (África, Ásia e o Pacífico e Américas). Constatamos que os padrões da transmissão da malária antes da introdução dos empreendimentos, as medidas de controle, os movimentos demográficos, os padrões comportamentais das comunidades humanas e a bionomia dos anofelinos locais determinarão se o estabelecimento de campos de irrigação e/ou usinas hidrelétricas podem influenciar negativamente na saúde das pessoas. São apresentados exemplos de medidas de controle bem sucedidas nesses cenários. A utilização de Sistemas de Informação Geográfico tem sido destacada como uma importante ferramenta para subsidiar o estudo e controle da malária em áreas sob impacto ambiental

Biodiversity assessment of Phlebotomine (Diptera: Psychodidae) in an environmental impacted area in Rio de Janeiro State, Brazil

From October 1994 to September 1996, in the municipality of Mangaratiba, Rio de Janeiro State, phlebotomines were captured on the walls of the houses by means of a manual suction tube and light traps, in the household, the peridomicile and in the forest. As it is an area undergoing a real expansion and an increment in the local tourism, with the purpose of assessing changes in the phlebotomine fauna caused by environmental changes in the region, new captures were made in the same location from October 2015 to September 2016, this time using only light traps. In the two phases of the study, a total of 6,681 phlebotomines were captured. The results indicated that Ny. intermedia and Mg. migonei are fully adapted to this anthropic environment, while Pi. fischeri was more abundant and eclectic, and was probably attracted to exercise hematophagy. Nyssomyia intermedia can be suggested as the main vector of the etiological agent of the American Tegumentary Leishmaniasis in the studied areas. Pintomyia fischeri can also transmit Leishmania braziliensis, both in the environment altered by human action, and in the wild environment. Phlebotomines were captured in greater numbers between 6 and 8 pm in the peridomicile and between 9 and 11 pm in the household. The highest densities of phlebotomines were recorded in December, January and February. Despite almost 20 years between the two studies in the municipality of Mangaratiba, there was no change in the profile of the phlebotomine fauna in general; however, there was a greater density of species of medical importance in areas that suffered environmental impacts

Ecologia de mosquitos (Diptera: Culicidae) em áreas do Parque Nacional da Serra da Bocaina, Brasil.I - Distribuição por habitat

OBJECTIVE: To assess the mosquito fauna in Serra da Bocaina National Park (PNSB), by collecting information through a general survey, and investigating the population behavior in habitats within the park with different vegetation. METHODS: Human bait collections were conducted once a month for both the forest and households, in diurnal and nocturnal periods, three time a day, throughout 24 months, from January 1991 to December 1992. RESULTS: A total of 11,808 adult mosquitoes belonging to 28 species were collected. Runchomyia reversa and Anopheles cruzii were the most abundant, reaching 52.5% and 17.9% of the total collected specimens, respectively. In the dense forest, Ru. reversa comprised 59.4% of the total, followed by Ru. frontosa with 10.5%, and An. cruzii with 9.9%. In the high altitude fields and in gallery forest, An. cruzii was the most abundant (48.1%) followed by Ru. reversa (28.1%). Inside households An. cruzii was also the most prominent species, representing 73.7% of the total for that location. Coquillettidia chrysonotum was the only species mainly seen in the household surroundings, where its distribution was: 14.9% (indoors), 19.4% (close to the house), and 65.7% (outdoors). An. cruzii and Ru. reversa were found throughout the whole year and captured every month. CONCLUSIONS: Mosquitoes in PNSB present an assynanthropic behavior, except for Cq. chrysonotum which lives preferentially in the household environment. Though An. cruzii is an assynantropic species it may approaches live near households and even invades and infest them for the blood meals. The occurrence of Aedes serratus in the household vicinity emphasizes its epidemiological importance as a potential vector of arboviruses. Sabethini are all exclusively sylvatic species.OBJETIVO: Estabelecer a influência exercida por três diferentes biótopos em áreas do Parque Nacional da Serra da Bocaina (PNSB) sobre a fauna local de mosquitos. MÉTODOS: Foram realizadas capturas mensais em ambiente silvestre e domiciliar, em isca humana, durante três diferentes períodos do dia, pelo período de 24 meses consecutivos, de janeiro de 1991 a dezembro de 1992. RESULTADOS: Foram capturados 11.808 espécimes adultos, pertencentes a 28 espécies. Ru. reversa e An. cruzii foram predominantes, respectivamente 52,5% e 17,9% do total de mosquitos. Ru. reversa representou 59,4% do total de espécimes no ambiente de mata fechada, seguida por Ru. frontosa com 10,5% e An. cruzii com 9,9%. No ambiente formado por campos de altitude e matas de galeria, o An. cruzii predominou com 48,1%, seguido por Ru. reversa com 28,1%. No ambiente modificado pelo homem, o An. cruzii predominou com 73,7% dos espécimes. Coquillettidia chrysonotum foi a única que se apresentou preferencialmente nesse biótopo: 14,9% no intra, 19,4% no peri e 65,7% no extradomicílio. An. cruzii e Ru. reversa foram constantes em todos os ambientes ao longo do ano. CONCLUSÕES: Com exceção de Cq. chrysonotum, com preferência pelo ambiente modificado pelo homem, os mosquitos apresentam hábitos assinantrópicos no PNSB. An. cruzii, embora assinantrópico, se aproxima e adentra o domicílio para realizar a hematofagia. A presença do Ae. serratus no extra e peridomicílio reforça a importância epidemiológica como vetora potencial de arboviroses. Os Sabethini apresentaram-se exclusivamente silvestres

Bionomia de mosquitos (Diptera: Culicidae) em áreas da Mata Atlântica no município de Itaguaí, estado do Rio de janeiro, Brasil: I. Frequência intra, peri e extradomiciliar

Along 24 consecutive months, from January 1984 to December 1986, mosquito captures were performed in a rural area of said municipality. Aiming to evaluate the comparative frequency of the mosquito species inside houses and in the immediate vicinity and far from houses, the captures were made in two types of domiciles - one permanently and the other only sporadically inhabited - as well as in surrounding woods. Variations in temperature, relative humidity and rainfall were locally recorded. A tendency for domiciliation became evident by the presence of Aedes scapularis in the human domiciles, mainly in those permantely inhabited. Culex quinquefasciatus showed to be adapted to live with humans also in rural areas, in which, in some instances, insecticides had to be used to keep in under control. Such observations, mainly in terms of Ae. scapularis, reinforce the possibility of those mosquitoes, under favourable conditions, becoming carries of arboviroses to humans in rural environments

Microscopia eletrônica de varredura de ovos de Haemagogus leucocelaenus (Diptera: Culicidae)

OBJECTIVE: To observe morphological details of the eggs of Haemagogus (Conopostegus) leucocelaenus, seen for the first time via scanning electron microscopy (SEM), with morphometric analysis of the main structures. METHODS: Eggs of Hg. leucocelaenus were obtained from females captured in the Biological Reserve of Tinguá, State of Rio de Janeiro. Some of the eggs were kept for hatching and others underwent processing for scanning electron microscopy studies. Three eggs were submitted to morphometric analysis. The material was fixed in 2.5% glutaraldehyde and postfixed in 1% osmium tetroxide, both in 0.1M, pH 7.2 sodium cacodylate buffer, then dehydrated in ethanol and dried using the critical point method. This was then set up on metallic supports, covered with gold and observed using the Jeol 5310 scanning electron microscope. Measurements were made with the aid of the Semafore analysis software coupled to the electron microscope. RESULTS: The eggs presented elliptical outlines of approximately 574 mm in length and 169 mm in width, with an egg index (l/w ratio) of 3.39 mm. The exochorion was extremely regular and had ornamentation that was usually hexagonal but sometimes pentagonal. Tubercles were observed on the chorionic cells, symmetrically arranged in relation to the longitudinal axis. Inside the cells, there were smaller, individualized tubercles, some arranged peripherally and others grouped to a greater or lesser extent in the center. The surface of the chorionic reticulum did not present rugosity. The micropylar apparatus was formed by a prominent continuous collar of 8.32 mm in thickness, with a slightly irregular surface. The micropylar disk was very evident, and was continuous with the collar. The micropyle was seen at the center of this disk, measuring 1.6 mm and with a micropylar apparatus of 27.3 mm in diameter. CONCLUSIONS: The ornamentation of the exochorion presents differences in relation to the tubercles of chorionic cells and the external chorionic reticulum between the eggs of Hg. Leucocelaenus, in comparison with the eggs of Hg. janthinomys and Hg. equinus, and also in relation to those of Aedes aegypti, Ae. albopictus and Ae bahamensis. In various aspects, the eggs of Hg. leucocelaenus have more resemblance to those of Hg. Equinus than those of Hg. janthinomys, with greater differences presented in relation to the eggs of Hg. spegazzinii and Hg. lucifer.OBJETIVO: Observar detalhes morfológicos de ovos de Haemagogus leucocelaenus visualizados pela primeira vez por microscopia eletrônica de varredura (MEV) e realizar morfometria das principais estruturas. MÉTODOS: Foram utilizados ovos de Hg. leucocelaenus provenientes de fêmeas capturadas na Reserva Biológica do Tinguá, RJ, sendo parte destinada à eclosão e outra ao processamento de MEV, dos quais três foram submetidos à análise morfométrica. O material foi fixado em glutaraldeído 2,5% e pós-fixado em tetróxido de ósmio 1%, ambos em tampão cacodilato de sódio 0.1M, pH 7.2, processado e observado ao MEV Jeol 5310. Medições foram realizadas com o auxílio do software de análise Semafore. RESULTADOS: Os ovos apresentaram contorno elíptico com aproximadamente 574 µm de comprimento e 169 µm de largura, sendo o índice do ovo (l/wratio) 3,39 µm. O exocório é extremamente regular, possuindo ornamentação hexagonal e algumas vezes pentagonal. Nas células coriônicas, observaram-se tubérculos simetricamente dispostos com relação ao eixo longitudinal, e, no interior delas, tubérculos menores, individualizados, dispostos na periferia, e poucos agrupados no centro. A superfície do retículo coriônico não apresentou rugosidades. O aparelho micropilar apresenta colar proeminente, contínuo, com disco micropilar bem evidente. CONCLUSÕES: A ornamentação do exocório apresenta diferenças em relação aos tubérculos das células coriônicas e ao retículo coriônico externo entre os ovos de Hg. leucocelaenus comparados aos ovos de Hg. janthinomys e Hg. equinus, bem como com relação aos de Aedes aegypti, Ae. albopictus e Ae bahamensis

Investigação preliminar das espécies de culicídeos do Pantanal Sul brasileiro e sua potencial importância na transmissão de arbovírus

In view of the high circulation of migratory birds and the environmental and climatic conditions which favor the proliferation of arthropods, the Brazilian Pantanal is susceptible to circulation of arboviruses. However, the amount of data concerning arbovirus vectors in this area is scarce; therefore the aim of this study was to conduct a preliminary investigation of Culicidae species in the Nhecolândia Sub-region of South Pantanal, Brazil and their potential importance in the arbovirus transmission. A total of 3684 specimens of mosquitoes were captured, 1689 of which caught in the rainy season of 2007, were divided into 78 pools and submitted to viral isolation, Semi-Nested RT-PCR and Nested RT-PCR, with a view to identifying the most important arboviruses in Brazil. Simultaneously, 70 specimens of ticks found blood-feeding on horses were also submitted to the same virological assays. No virus was isolated and viral nucleic-acid detection by RT-PCR was also negative. Nevertheless, a total of 22 Culicidae species were identified, ten of which had previously been reported as vectors of important arboviruses. The diversity of species found blood-feeding on human and horse hosts together with the arboviruses circulation previously reported suggest that the Nhecolândia Sub-region of South Pantanal is an important area for arbovirus surveillance in Brazil.Regiões como o Pantanal brasileiro, que apresentam fatores como riqueza de fauna silvestre incluindo circulação de aves migratórias e condições ambientais e climáticas favoráveis à proliferação de artrópodes estão potencialmente sujeitas à circulação de arbovírus. Entretanto, poucos trabalhos foram realizados acerca da presença de arbovírus em potenciais vetores no Pantanal. Neste sentido o principal objetivo deste trabalho foi conduzir uma investigação preliminar para presença de arbovírus em amostragens de culicídeos capturados na Sub-região da Nhecolândia no Pantanal Sul. Um total de 3684 mosquitos foi capturado, dos quais 78 grupos compondo uma amostragem de 1789 espécimes foram submetidos às técnicas de isolamento viral e RT-PCR para os mais importantes arbovírus no Brasil. Simultaneamente, 70 espécimes de carrapatos capturados durante hematofagia em cavalos também foram submetidos à pesquisa viral. Não houve isolamento viral em nenhuma amostra analisada e os resultados de detecção de ácido nucléico viral foram também negativos. Entretanto, foram identificadas 22 espécies de culicídeos, dez das quais previamente reportadas como vetores de importantes arbovírus. A competência vetorial de espécies capturadas durante hematofagia em humanos e cavalos aliada ao relato prévio de circulação de arbovírus sugerem a Sub-região da Nhecolândia como uma importante área de vigilância para arbovírus no Centro-Oeste do Brasil

West Nile Virus, Venezuela

Submitted by Sandra Infurna ([email protected]) on 2020-04-01T17:32:07Z No. of bitstreams: 1 AnthonyE_Guimaraes_etal_IOC_2007.pdf: 108341 bytes, checksum: db1489aeeb51b9f823abd6e1273378ef (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2020-04-01T17:51:00Z (GMT) No. of bitstreams: 1 AnthonyE_Guimaraes_etal_IOC_2007.pdf: 108341 bytes, checksum: db1489aeeb51b9f823abd6e1273378ef (MD5)Made available in DSpace on 2020-04-01T17:51:00Z (GMT). No. of bitstreams: 1 AnthonyE_Guimaraes_etal_IOC_2007.pdf: 108341 bytes, checksum: db1489aeeb51b9f823abd6e1273378ef (MD5) Previous issue date: 2007University of Massachusetts Medical School. Center for Infectious Disease and Vaccine Research. Worcester, MA, USA.Universidad de Carabobo Biomed. Maracay, Venezuela.Universidad Central de Venezuela. Caracas, Venezuela.Coleccion Ornitologica Phelps. Caracas, Venezuela.New York State Department of Health. Albany, New York, USA / State University of New York at Albany. Albany, New York, USA.New York State Department of Health. Albany, New York, USA / State University of New York at Albany. Albany, New York, USA.New York State Department of Health. Albany, New York, USA / State University of New York at Albany. Albany, New York, USA.Universidad Central de Venezuela. Maracay, Venezuela.Instituto Nacional de Investigaciones Agrícolas. Maracay, Venezuela.Universidad Central de Venezuela, Caracas, VenezuelaFundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.Centers for Disease Control and Prevention. San Juan, Puerto Rico, USA.Universidad del Zulia. Maracaibo, Venezuela.Universidad de Carabobo Biomed. Maracay, Venezuela.Ministerio de Salud Insalud. Carabobo, Venezuela.Universidad Central de Venezuela, Caracas, VenezuelaUniversidad de Carabobo Biomed. Maracay, Venezuela.Centers for Disease Control and Prevention.Fort Collins, Colorado, USA.Harvard School of Public Health. Boston, Massachusetts, USA.New York State Department of Health. Albany, New York, USA / State University of New York at Albany. Albany, New York, USA