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Lima-Camara T.N.,Programa de Computacao Cientifica | Codeco C.T.,Programa de Computacao Cientifica | Honorio N.A.,Laboratorio Of Transmissores Of Hematozoarios | Bruno R.V.,Instituto Oswaldo Cruz Fiocruz | And 2 more authors.
Memórias do Instituto Oswaldo Cruz | Year: 2013

Dengue is one of the world's most important mosquito-borne diseases and is usually transmitted by one of two vector species: Aedes aegypti or Aedes albopictus . These two diurnal mosquitoes are frequently found coexisting in similar habitats, enabling interactions between adults, such as cross-mating. The objective of this study was to assess cross-mating between Ae. aegypti females and Ae. albopictus males under artificial conditions and evaluate the locomotor activity of Ae. aegypti virgin females injected with male accessory gland (MAG) homogenates to infer the physiological and behavioural responses to interspecific mating. After seven days of exposure, 3.3-16% of Ae. aegypti females mated with Ae. albopictus males. Virgin Ae. aegypti females injected with conspecific and heterospecific MAGs showed a general decrease in locomotor activity compared to controls and were refractory to mating with conspecific males. The reduction in diurnal locomotor activity induced by injections of conspecific or heterospecific MAGs is consistent with regulation of female reproductive activities by male substances, which are capable of sterilising female Ae. aegypti through satyrisation by Ae. albopictus. Source

Maciel-de-Freitas R.,Laboratorio Of Transmissores Of Hematozoarios | Aguiar R.,Servico de Jornalismo e Comunicacao | Bruno R.V.,Laboratorio Of Biologia Molecular Of Insetos | Guimaraes M.C.,Institute Comunicacao e Informacao Cientifica e Tecnologica | And 5 more authors.
Memorias do Instituto Oswaldo Cruz | Year: 2012

In this opinion paper, we discuss the potential and challenges of using the symbiont Wolbachia to block mosquito transmitted diseases such as dengue, malaria and chikungunya in Latin America. Source

Gibson G.,Escola Nacional de Saude Publica | Souza-Santos R.,Escola Nacional de Saude Publica | San Pedro A.,Escola Nacional de Saude Publica | Alves Honorio N.,Laboratorio Of Transmissores Of Hematozoarios | Sa Carvalho M.,Programa de Computacao Cientifi ca
Revista da Sociedade Brasileira de Medicina Tropical | Year: 2014

Introduction: This study aimed to analyze the relationship between the incidence of severe dengue during the 2008 epidemic in Rio de Janeiro, Brazil, and socioeconomic indicators, as well as indicators of health service availability and previous circulation of the dengue virus serotype-3 (DENV-3). Methods: In this ecological study, the units of analysis were the districts of Rio de Janeiro. The data were incorporated into generalized linear models, and the incidence of severe dengue in each district was the outcome variable. Results: The districts with more cases of dengue fever in the 2001 epidemic and a higher percentage of residents who declared their skin color or race as black had higher incidence rates of severe dengue in the 2008 epidemic [incidence rate ratio (IRR)= 1.21; 95% confi dence interval (95%CI)= 1.05-1.40 and IRR= 1.34;95%CI= 1.16-1.54, respectively]. In contrast, the districts with Family Health Strategy (FHS) clinics were more likely to have lower incidence rates of severe dengue in the 2008 epidemic (IRR= 0.81;95%CI= 0.70-0.93). Conclusions: At the ecological level, our fi ndings suggest the persistence of health inequalities in this region of Brazil that are possibly due to greater social vulnerability among the selfdeclared black population. Additionally, the protective effect of FHS clinics may be due to the ease of access to other levels of care in the health system or to a reduced vulnerability to dengue transmission that is afforded by local practices to promote health. © 2014, Sociedade Brasileira de Medicina Tropical. All Rights Reserved. Source

Maciel-De-Freitas R.,Laboratorio Of Transmissores Of Hematozoarios | Da Silva Lima A.W.,Laboratorio Of Fisiologia E Controle Of Artropodes Vetores | Araujo S.C.,Laboratorio Of Fisiologia E Controle Of Artropodes Vetores | Lima J.B.P.,Laboratorio Of Fisiologia E Controle Of Artropodes Vetores | And 7 more authors.
Memorias do Instituto Oswaldo Cruz | Year: 2014

Currently, sticky traps are regularly employed to assist in the surveillance of Aedes aegypti infestation. We tested two alternative procedures for specimen identification performed by local health agents: directly in the field, as recommended by certain manufacturers, or after transportation to the laboratory. A total of 384 sticky traps (MosquiTRAP) were monitored monthly during one year in four geographically representative Brazilian municipalities. When the same samples were inspected in the field and in the laboratory, large differences were noted in the total number of mosquitoes recorded and in the number of specimens identified as Ae. aegypti by both procedures. Although field identification has the potential to speed vector surveillance, these results point to uncertainties in the evaluated protocol. © 2014 Fundacao Oswaldo Cruz. All rights reserved. Source

Villela D.A.M.,Fundacao Oswaldo Cruz | Codeco C.T.,Fundacao Oswaldo Cruz | Figueiredo F.,Fundacao Oswaldo Cruz | Garcia G.A.,Laboratorio Of Transmissores Of Hematozoarios | And 2 more authors.
PLoS ONE | Year: 2015

Strategies to minimize dengue transmission commonly rely on vector control, which aims to maintain Ae. aegypti density below a theoretical threshold. Mosquito abundance is traditionally estimated from mark-release-recapture (MRR) experiments, which lack proper analysis regarding accurate vector spatial distribution and population density. Recently proposed strategies to control vector-borne diseases involve replacing the susceptible wild population by genetically modified individuals' refractory to the infection by the pathogen. Accurate measurements of mosquito abundance in time and space are required to optimize the success of such interventions. In this paper, we present a hierarchical probabilistic model for the estimation of population abundance and spatial distribution from typical mosquito MRR experiments, with direct application to the planning of these new control strategies. We perform a Bayesian analysis using the model and data from two MRR experiments performed in a neighborhood of Rio de Janeiro, Brazil, during both low- and high-dengue transmission seasons. The hierarchical model indicates that mosquito spatial distribution is clustered during the winter (0.99 mosquitoes/premise 95% CI: 0.80-1.23) and more homogeneous during the high abundance period (5.2 mosquitoes/premise 95% CI: 4.3-5.9). The hierarchical model also performed better than the commonly used Fisher-Ford's method, when using simulated data. The proposed model provides a formal treatment of the sources of uncertainty associated with the estimation of mosquito abundance imposed by the sampling design. Our approach is useful in strategies such as population suppression or the displacement of wild vector populations by refractory Wolbachia-infected mosquitoes, since the invasion dynamics have been shown to follow threshold conditions dictated by mosquito abundance. The presence of spatially distributed abundance hotspots is also formally addressed under this modeling framework and its knowledge deemed crucial to predict the fate of transmission control strategies based on the replacement of vector populations. © 2015 Villela et al. Source

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