Juliana Maria Trindade Bezerra

Distinct variation in vector competence among nine field populations of Aedes aegypti from a Brazilian dengue-endemic risk city

BackgroundIn Brazil, dengue epidemics erupt sporadically throughout the country and it is unclear if outbreaks may initiate a sustainable transmission cycle. There are few studies evaluating the ability of Brazilian Aedes aegypti populations to transmit dengue virus (DENV). The aim of this study was to compare DENV susceptibility of field-captured Ae. aegypti populations from nine distinct geographic areas of the city of Belo Horizonte in 2009 and 2011. Infection Rate (IR), Vector Competence (VC) and Disseminated Infection Rate (DIR) were determined.MethodsAedes aegypti eggs from each region were collected and reared separately in an insectary. Adult females were experimentally infected with DENV-2 and the virus was detected by qPCR in body and head samples. Data were analyzed with the Statistical Package for the Social Sciences version 17.ResultsIR varied from 40.0% to 82.5% in 2009 and 60.0% to 100.0% in 2011. VC ranged from 25.0% to 77.5% in 2009 and 25.0% to 80.0% in 2011. DIR oscillated from 68.7% to 100.0% in 2009 and 38.4% to 86.8 in 2011. When the results were evaluated by a logistic model using IR as covariate, North, Barreiro, South-Central and Venda Nova showed the strongest association in 2009. In 2011, a similar association was observed for South-Central, Venda Nova, West and Northeast regions. Using VC as covariate, South-Central and Venda Nova showed the most relevant association in 2009. In 2011, South-Central, Venda Nova and Barreiro presented the greatest revelation associations. When DIR data were analyzed by logistic regression models, Pampulha, South-Central, Venda Nova, West, Northeast and East (2009) as well as South-Central, Venda Nova and West (2011) were the districts showing the strongest associations.ConclusionsWe conclude that Ae. aegypti populations from Belo Horizonte exhibit wide variation in vector competence to transmit dengue. Therefore, vector control strategies should be adapted to the available data for each region. Further analysis should be conducted to better understand the reasons for this large variability in vector competence and how these parameters correlate with epidemiological findings in subsequent years.

Conhecimentos de estudantes sobre Leishmaniose Visceral em escolas públicas de Caxias, Maranhão, Brasil

(2) Explique, resumidamente, exatamente a que corresponde essa função (tendo em vista que a maioria da população não conhece o funcionamento hierárquico da Polícia). Resposta: As principais funções do Diretor Geral de Saúde são: I. Coordenar as Unidades de Saúde da PMERJ que hoje compreendem 2 Hospitais, 4 Policlínicas, localizadas nos bairros de Cascadura, Olaria, São João de Meriti e na Cidade de Campos dos Goitacazes e um Centro de Fisioterapia e Reabilitação; II. Implementar políticas de saúde para o Sistema de Saúde da Polícia Militar; III. Gerir junto ao Comandante Geral e ao Chefe do Estado Maior da Polícia Militar os recursos do Fuspom (Fundo de Saúde da Polícia Militar); IV. Planejar junto ao Comando da Corporação o apoio de Resgate e Remoção nas ações de campo da tropa da PMERJ; V. Planejar, implementar a assistência médica hospitalar aos Policiais Militares e seus dependentes diretos. Este Diretor Geral de Saúde em atenção às questões formuladas como parte da entrevista da Revista Ciência & Saúde Coletiva da Fundação Oswaldo Cruz presta as seguintes informações:

Variation in Aedes aegypti (Linnaeus) (Diptera, Culicidae) infestation in artificial containers in Caxias, state of Maranhão, Brazil

INTRODUCTION Dengue is a serious public health problem worldwide, with cases reported annually in tropical and subtropical regions. Aedes aegypti (Linnaeus, 1762), the main vector of dengue, is a domiciliary species with high dispersal and survival capacities and can use various artificial containers as breeding sites. We assessed potential container breeding sites of A. aegypti in the municipality of Caxias, Maranhão, Brazil. METHODS In the initial phase, we analyzed 900 properties in 3 neighborhoods during the dry and rainy seasons (August-October 2005 and February-April 2006, respectively). During the second sampling period, September 2006-August 2007, we used 5 assessment cycles for 300 properties in a single neighborhood. RESULTS During the dry and rainy seasons, water-storage containers comprised 55.7% (n = 1,970) and 48.5% (n = 1,836) of the total containers inspected, and showed the highest productivity of immature A. aegypti; we found 23.7 and 106.1 individuals/container, respectively, in peridomicile sites. In intradomicile sites, water-storage containers were also the most important breeding sites with 86.4% (n = 973) and 85.6% (n = 900) of all containers and a mean of 7.9 and 108.3 individuals/container in the dry and rainy seaso-October 2006 (1,342). The highest number of positives (70) was recorded in May, mostly (94%) in storage containers. CONCLUSIONS Storage containers are the principal and most productive A. aegypti breeding sites and are a major contributing factor to the maintenance of this vector in Caxias.

Aedes (Stegomyia) albopictus' dynamics influenced by spatiotemporal characteristics in a Brazilian dengue-endemic risk city.

Brazil reported the majority of the dengue cases in Americas during the last two decades, where the occurrence of human dengue cases is exclusively attributed to the Aedes (Stegomyia) aegypti (Linnaeus). Nowadays, other recognized Dengue virus (DENV) vector in Asian countries, Aedes (Stegomyia) albopictus (Skuse), has been detected in more than half of the 5565 Brazilian municipalities. Therefore, the aim of the present study was to investigate the presence of, and determine the Ae. albopictus’ dynamics influenced by spatiotemporal characteristics in a dengue-endemic risk city of Belo Horizonte, Minas Gerais State’s capital. Aedes albopictus were collected across four consecutive DENV transmission seasons from 2010 to 2014. These mosquitoes were caught in three selected districts, which had been reported in the previous ten years as having high mosquito densities and an elevated concentration of human dengue cases during epidemic seasons. All field-caught Ae. albopictus was individually processed by real-time RT-PCR, to research the DENV presence. The third season (p < 0.05) and the Pampulha district (p < 0.05) had the highest proportions of field-caught Ae. albopictus, respectively. The second season had the highest proportion of DENV-infected field-caught females (p < 0.05), but there was no difference among the proportions of DENV-infected Ae. albopictus when comparing the collection in the three districts (p = 0.98). Minimum (p = 0.004) and maximum (p < 0.0001) temperature were correlated with the field-caught Ae. albopictus in four different periods and districts. In the generalized linear model of Poisson, the field-caught DENV-infected Ae. albopictus (p = 0.005), East district (p = 0.003), minimum temperature (p < 0.0001) and relative humidity (p = 0.001) remained associated with the total number of human dengue cases. Our study demonstrated that the number of field-caught DENV-infected Ae. albopictus was inversed correlated with the number of human dengue cases. Our study raises the possibility that the DENV circulating in mosquitoes Ae. albopictus is happening in non-epidemic periods, showing that this species may be keeping only the presence of the virus in nature. Further long-term studies are necessary to better understand the role of Ae. albopictus in DENV transmission and or its vectorial competence in Belo Horizonte and in other endemic cities in Brazil and in the New World countries.

Occurrence of Aedes aegypti (Diptera, Culicidae) in a Dengue Transmission Area at Coastal Maranhão State, Brazil

This study aimed to estimate the occurrence of Aedes aegypti adults at distinct climatic seasons at neighbor- hoods from the municipality of Sao Luis, Maranhao State, Brazil, as well as to verify the presence of Dengue virus (DENV) in the specimens collected. A total of 320 properties were visited in eight neighborhoods that were previously randomly chosen. Samplings were made at three periods: dry season/2008, rainy season/2009 and dry season/2009. A to- tal of 563 Ae. aegypti mosquitoes were collected, with 141 of them collected during dry season/2008, 272 during rainy season/2009 and the remnant, during dry season/2009. Specimen were divided into lots and subjected to RT-semi-nested- PCR analysis and virus isolation was carried out using cell culture (C6/36 clone) of Ae. albopictus. The number of adults significantly varied at the neighborhoods of Coreia de Baixo, Lira, Joao Paulo, and Conjunto Cohatrac I. Molecular anal- yses of specimens showed no positivity for DENV. At the municipality of Sao Luis, seasonal climate variation might in- fluence the density of Ae. aegypti adults, however, other factors such as population density, sanitation conditions, and the presence of mosquito breeding sites ought to be assessed as important parameters influencing vector dispersion.

DIVERSIDADE DE ANOPHELES E INFECÇÃO POR MALÁRIA NA ZONA DOS COCAIS, ESTADO DO MARANHÃO, BRASIL

A survey of the Anopheles species was conducted in the municipality of São Mateus, in the state of Maranhão. Species hematophagy habits, the influence of seasonality as well as the vector’s infection by Plasmodium were studied. The female Anopheles mosquitoes were captured between February and December 2010 and in March 2012, from 18h00 to 21h00, in intra and peridomiciles. PCR was used for the infection studies. A total 615 specimens of Anopheles were captured, of which 223 (36.2%) in the locality of Piquizeiro and 392 (63.8%) on the Retiro Velho Farm belonging to the species An. nuneztovari, An. darlingi, An. triannulatus, An. albitarsise, and An. oswaldoi. In Piquizeiro most specimens were captured in the intradomiciliary area, while on the Retiro Velho Farm they were mostly found in the peridomiciliary area. The results show the influence of seasonality and time of capture in the hematophagy frequency of the captured Anopheles. The negative result for Plasmodium infection demonstrates a reduction in the number of malaria cases in the State during the study period.