Algoritmo genético aplicado ao controle do mosquito transmissor da dengue

Pós-graduação em Biometria - IBB

Estudo da filogenia dos anofelinos brasileiros do subgênero Nyssorhynchus e padronização da amplificação dos genes do receptor do peptídeo sexual (SPR) e do peptídeo sexual (SP)

Pós-graduação em Ciências Biológicas (Genética) - IBB

Análise temporal da dinâmica populacional de Aedes aegypti

Dengue virus is a major public health problem worldwide. Aedes (Stegomyia) aegypti is the main dengue vector. Since there is no specific treatment or effective vaccine, control measure is focused on vector control. It is believed that population density is higher in the warmer/rainy season than in cold/dry. The study aimed to genetically characterize population dynamics of Ae. aegypti during climatic variations. Collections were performed at least once in both periods over five years by oviposition traps at Botucatu city. The technique of TaqMan allelic discrimination was used for genetic analysis, in which SNPs from nine genes distributed on three chromosomes of the mosquito were genotyped. Bayesian analysis did not show variance on population structure over the five year period. The percentage of variation among samples in statistical analysis was low (Fst = 0.0028, p = 0.7634), furthermore the allele frequencies were constant. The results show that despite wide variation in the density of adults, population size does not vary. Therefore, there is variation in the prevalence of the species life stages: adults in warmer/rainy, and possibly eggs in cold/dry, resulting in different control strategies for each period. Moreover, estimation of population size should not consider only winged adults, but all other found life stages forms

Global stabilizing feedback law for a problem of biological control of mosquito-borne diseases

The control of the spread of dengue fever by introduction of the intracellular parasitic bacterium Wolbachia in populations of the vector Aedes aegypti, is presently one of the most promising tools for eliminating dengue, in the absence of an efficient vaccine. The success of this operation requires locally careful planning to determine the adequate number of mosquitoes carrying the Wolbachia parasite that need to be introduced into the natural population. The latter are expected to eventually replace the Wolbachia-free population and guarantee permanent protection against the transmission of dengue to human. In this paper, we propose and analyze a model describing the fundamental aspects of the competition between mosquitoes carrying Wolbachia and mosquitoes free of the parasite. We then introduce a simple feedback control law to synthesize an introduction protocol, and prove that the population is guaranteed to converge to a stable equilibrium where the totality of mosquitoes carry Wolbachia. The techniques are based on the theory of monotone control systems, as developed after Angeli and Sontag. Due to bistability, the considered input-output system has multivalued static characteristics, but the existing results are unable to prove almost-global stabilization, and ad hoc analysis has to be conducted.

A eliminação do mosquito do dengue em ambientes residenciais: uma questão de cuidado ambiental?

Dengue is currently considered one of the most relevant public health problems worldwide. Studies indicate the surroundings of the houses as the preferred sites for the proliferation of Aedes aegypti. The residential areas are privileged environments for human development and contribute to the formation of the individual s identity and for the establishment of affective, social and cultural bonds. The purpose of this study was to investigate possible links between psychological indicators of pro-environmentalism and conservation status of residential backyards. Data collection was performed in 147 homes and methodological strategy involved the use of interview, the Scale of Ecocentric and Anthropocentric Environmentalism, Scale of Consideration of Future Consequences and a tool for environmental evaluation. It was found that the participants expressed as environmental practices the garbage recycling, besides they had the knowledge of how the transmission of dengue occurs. These residents showed ecofriendly motivated commitment: pro-environmentalist ecocentric and anthropocentric. In evaluating the backyard it was verified that the conservation conditions, in almost half of the homes, appeared as carelessness on the part of residents and those conditions are conducive to the proliferation of Aedes aegypti. The pro-environmentalists and guidance for the future identified by the scales were not associated with the conservation status of the backyards. However, it was found that the trends of reduction and stability of infestation levels are associated with self-reported environmental care. These results can contribute to the discussion and design of new mosquito control actions and practices of education and health information among the population

Desenvolvimento de metodologia high-throughput para estudo populacional do mosquito Aedes aegypti e comparação de dados de genes mitocondriais

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desenvolvimento de marcadores SNPs (Single Nucleotide Polymorphisms) para estudos populacionais do mosquito Aedes aegypti no Brasil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Otimização multiobjetivo no controle da dengue

Pós-graduação em Biometria - IBB

Analise microbiológica da flora intestinal do mosquito Aedes Aegypti através do sequenciamento do gene 16S rRNA na plataforma Illumina MiSeq

Dengue é uma arbovirose que afeta cerca de 100 milhões de pessoas anualmente, em mais de 100 países situados nas regiões tropicais e subtropicais. Foi considerada a doença viral que mais cresceu no ultimo ano, repercutindo em impactos sociais e econômicos nas regiões endêmicas devido às altas taxas de morbidade e mortalidade desencadeadas pela infecção. O principal vetor da dengue é o mosquito Aedes aegypti, presente em toda a faixa tropical e subtropical. Por apresentar hematofagia antropofílica, rápido desenvolvimento e características comportamentais especificas, é um excelente transmissor do vírus dengue. Medidas de controle da disseminação da dengue são restritas à eliminação do mosquito vetor, e um tratamento específico ainda não foi desenvolvido, bem como a criação de uma vacina que previna simultaneamente a infecção pelos quatro sorotipos do arbovírus. Uma característica que determina a disseminação de doenças é a alta competência vetorial de seus mosquitos transmissores, que tem sido associada à composição da microbiota intestinal do inseto. As bactérias presente no intestino do mosquito exercem funções relacionadas a sua nutrição, desenvolvimento e reprodução, e são também um importante fator na eliminação de patógenos, por interferirem diretamente na atividade viral, ou indiretamente a partir da ativação das vias antivirais pelos micro-organismos. Dessa forma, este trabalho visa estudar a diversidade microbiana intestinal do mosquito Aedes aegypti em diferentes estágios de vida, através de sequenciamento de última geração com a plataforma MiSeq Illumina

Difference in mosquito species (Diptera: Culicidae) and the transmission of Ross River Virus between coastline and inland areas in Brisbane, Australia

This study examined the distribution of major mosquito species and their roles in the transmission of Ross River virus (RRV) infection for coastline and inland areas in Brisbane, Australia (27°28′ S, 153°2′ E). We obtained data on the monthly counts of RRV cases in Brisbane between November 1998 and December 2001 by statistical local areas from the Queensland Department of Health and the monthly mosquito abundance from the Brisbane City Council. Correlation analysis was used to assess the pairwise relationships between mosquito density and the incidence of RRV disease. This study showed that the mosquito abundance of Aedes vigilax (Skuse), Culex annulirostris (Skuse), and Aedes vittiger (Skuse) were significantly associated with the monthly incidence of RRV in the coastline area, whereas Aedes vigilax, Culex annulirostris, and Aedes notoscriptus (Skuse) were significantly associated with the monthly incidence of RRV in the inland area. The results of the classification and regression tree (CART) analysis show that both occurrence and incidence of RRV were influenced by interactions between species in both coastal and inland regions. We found that there was an 89% chance for an occurrence of RRV if the abundance of Ae. vigifax was between 64 and 90 in the coastline region. There was an 80% chance for an occurrence of RRV if the density of Cx. annulirostris was between 53 and 74 in the inland area. The results of this study may have applications as a decision support tool in planning disease control of RRV and other mosquito-borne diseases.

The importance of mosquito behavioural adaptations to malaria control in Africa

Over the past decade the use of long-lasting insecticidal nets (LLINs), in combination with improved drug therapies, indoor residual spraying (IRS) and better health infrastructure, has helped reduce malaria in many African countries for the first time in a generation. However, insecticide resistance in the vector is an evolving threat to these gains. We review emerging and historical data on behavioural resistance in response to LLINs and IRS. Overall the current literature suggests behavioural and species changes may be emerging, but the data are sparse and, at times unconvincing. However, preliminary modelling has demonstrated that behavioural resistance could have significant impacts on the effectiveness of malaria control. We propose seven recommendations to improve understanding of resistance in malaria vectors. Determining the public health impact of physiological and behavioural insecticide resistance is an urgent priority if we are to maintain the significant gains made in reducing malaria morbidity and mortality.

Governing the dangerous classes : welcome to E-Nose, CCTV and the Mosquito

In urban locations in Australia and elsewhere, public space may be said to be under attack from developers and also from attempts by civic authorities to oversee and control it (Davis 1995, Mitchell 2003, Watson 2006, Iveson 2006). The use of public space use by young people in particular, raises issues in Australia and elsewhere in the world. In a context of monitoring and control procedures, young people’s use of public space is often viewed as a threat to the prevailing social order (Loader 1996, White 1998, Crane and Dee 2001). This paper discusses recent technological developments in the surveillance, governance and control of public space used by young people, children and people of all ages.

Impact of Wolbachia on infection with chikungunya and yellow fever viruses in the mosquito vector Aedes aegypti

Incidence of disease due to dengue (DENV), chikungunya (CHIKV) and yellow fever (YFV) viruses is increasing in many parts of the world. The viruses are primarily transmitted by Aedes aegypti, a highly domesticated mosquito species that is notoriously difficult to control. When transinfected into Ae. aegypti, the intracellular bacterium Wolbachia has recently been shown to inhibit replication of DENVs, CHIKV, malaria parasites and filarial nematodes, providing a potentially powerful biocontrol strategy for human pathogens. Because the extent of pathogen reduction can be influenced by the strain of bacterium, we examined whether the wMel strain of Wolbachia influenced CHIKV and YFV infection in Ae. aegypti. Following exposure to viremic blood meals, CHIKV infection and dissemination rates were significantly reduced in mosquitoes with the wMel strain of Wolbachia compared to Wolbachia-uninfected controls. However, similar rates of infection and dissemination were observed in wMel infected and non-infected Ae. aegypti when intrathoracic inoculation was used to deliver virus. YFV infection, dissemination and replication were similar in wMel-infected and control mosquitoes following intrathoracic inoculations. In contrast, mosquitoes with the wMelPop strain of Wolbachia showed at least a 10(4) times reduction in YFV RNA copies compared to controls. The extent of reduction in virus infection depended on Wolbachia strain, titer and strain of the virus, and mode of exposure. Although originally proposed for dengue biocontrol, our results indicate a Wolbachia-based strategy also holds considerable promise for YFV and CHIKV suppression.

A systematic review of mathematical models of mosquito-borne pathogen transmission: 1970-2010

Mathematical models of mosquito-borne pathogen transmission originated in the early twentieth century to provide insights into how to most effectively combat malaria. The foundations of the Ross–Macdonald theory were established by 1970. Since then, there has been a growing interest in reducing the public health burden of mosquito-borne pathogens and an expanding use of models to guide their control. To assess how theory has changed to confront evolving public health challenges, we compiled a bibliography of 325 publications from 1970 through 2010 that included at least one mathematical model of mosquito-borne pathogen transmission and then used a 79-part questionnaire to classify each of 388 associated models according to its biological assumptions. As a composite measure to interpret the multidimensional results of our survey, we assigned a numerical value to each model that measured its similarity to 15 core assumptions of the Ross–Macdonald model. Although the analysis illustrated a growing acknowledgement of geographical, ecological and epidemiological complexities in modelling transmission, most models during the past 40 years closely resemble the Ross–Macdonald model. Modern theory would benefit from an expansion around the concepts of heterogeneous mosquito biting, poorly mixed mosquito-host encounters, spatial heterogeneity and temporal variation in the transmission process.