BackgroundThe study of the genetic structure of Aedes aegypti is essential to understanding their population dynamics as well as for the analysis of factors responsible for their resistance and ecological adaptation. The use of molecular markers in identifying differences amongst populations of Ae. aegypti in different geographical areas as well as the temporal variation of the vector populations has contributed to the improvement of vector control strategies. The present study aims to determine the genetic variability of Ae. aegypti populations in a small geographical area (state of Sergipe, Northeastern Brazil) by means of inter-simple sequence repeat (ISSR) and single nucleotide polymorphism (SNP) molecular markers.ResultsISSR markers revealed a more heterogeneous pattern of genetic diversity among the populations with an expected heterozygosity (H
E) ranging from 0.261 ± 0.03 to 0.120 ± 0.032, while a similar trend was detected through SNPs across populations with an H
E between 0.375 ± 0.054 and 0.269 ± 0.042. The population’s genetic differentiation assessed with ISSR and SNP markers indicated a very low structuring among the populations with the highest diversity observed within the populations 72 % (ISSR) and 92 % (SNP). Clustering analysis also suggested little variation among populations: the seven populations were grouped into only three ISSR clusters and a single panmictic group based on SNP markers. The present study identified a close relationship between the populations, which probably results mainly from passive gene flow between mosquitoes from distinct geographic regions, influenced by humans commuting along roads.ConclusionsThere was an intense migration of mosquitos across municipalities, leading to a potential increase in risk of arbovirus and insecticide resistance associated-alleles spreading between mosquito populations.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1814-9) contains supplementary material, which is available to authorized users.
In order to find new alternatives for vector control and personal protection, we evaluated the larvicidal and repellent activity of essentials oils from plants found in the Northeast of Brazil against Aedes aegypti Linnaeus mosquitoes. The plants tested include Xylopia laevigata, Xylopia frutescens, and Lippia pedunculosa and their major compounds, piperitenone oxide, and (R)-limonene. The essential oil of L. pedunculosa and its major volatile compounds were shown to be toxic for Ae. aegypti larvae with a LC lower than 60 ppm. The essential oil of plants from the Xylopia genus, on the other hand, showed no activity against Ae. aegypti, proving to be toxic to mosquito larvae only when concentrations were higher than 1000 ppm. All plants tested provided some degree of protection against mosquitoes landing, but only the essential oil of L. pedunculosa and the volatile compound piperitenone oxide suppressed 100% of mosquitoes landing on human skin, in concentrations lower than 1%. Among the plants studied, the essential oil of L. pedunculosa and its volatiles compounds have shown the potential for the development of safe alternative for mosquito larvae control and protection against Ae. aegypti mosquito bites.
casos positivos apresentaram alta carga parasitária (média de 7,9% ± 2,1%). De todos os casos positivos, 42.779 foram tratados (média de 68,7% ± 9,5%). O percentual de casos com alta carga parasitária apresentou tendência crescente estatisticamente significante (5,7% ao ano). Apresentaram tendência decrescente estatisticamente significante a adesão de municípios ao PCE (4,0% por ano) e o número de exames realizados (9,6% por ano). Em relação à distribuição espacial da esquistossomose, em 2011, ano de maior adesão de municípios ao PCE, cinco, 30 e 10 municípios foram, respectivamente, considerados de alta, média e baixa endemicidade. Em 2017, Siriri foi considerado como de alta endemicidade, 20 municípios foram de média endemicidade e cinco de baixa endemicidade. CONCLUSÃO: As ações do PCE diminuíram em Sergipe, o que somado à aparente subnotificação e ao aumento de casos com alta carga parasitária, compromete os ganhos obtidos no controle da doença.
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