scholarly journals Genetic structure of Aedes aegypti in the city of Córdoba (Argentina), a recently reinfested area

2009 ◽  
Vol 104 (4) ◽  
pp. 626-631 ◽  
Author(s):  
Norma B Julio ◽  
Marina B Chiappero ◽  
Hernán J Rossi ◽  
Juan C Rondan Dueñas ◽  
Cristina N Gardenal
Keyword(s):  
Genetic Structure ◽  
Aedes Aegypti ◽  
The City

scholarly journals Variation over space and time of Aedes aegypti in Phnom Penh (Cambodia): genetic structure and oral susceptibility to a dengue virus

2003 ◽  
Vol 82 (3) ◽  
pp. 171-182 ◽  
Author(s):  
CHRISTOPHE PAUPY ◽  
NGAN CHANTHA ◽  
MARIE VAZEILLE ◽  
JEAN-MARC REYNES ◽  
FRANCOIS RODHAIN ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Aedes Aegypti ◽  
Dengue Virus ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Dry Season ◽  
City Centre ◽  
Phnom Penh ◽  
Space And Time ◽  
The City

We studied spatial and temporal variation in 20–23 Aedes aegypti samples collected in Phnom Penh and its suburbs to estimate the population genetic structure using allozymes and the susceptibility to a dengue-2 virus. Based on seven allozyme systems, we detected low levels of genetic exchanges (i.e. high, significant FST values) between populations collected in the city centre, and different patterns of genetic structure for samples collected in the suburbs, depending on the type of environment and the date of collection. In the southern suburbs and the Chroy Chang Var Peninsula, differentiation became highly significant at the end of the dry season, whereas the opposite situation was observed for collections from the northern suburbs. Vector competence assessed by oral infections with a dengue-2 virus was lower for samples collected in the city centre than in the suburbs. A significant decrease of dengue susceptibility was observed in populations during the dry season. This study allows a model of Ae. aegypti population functioning in Phnom Penh to be suggested. Dynamics of dengue virus diffusion depend on the population genetic structure of the vector and its evolution over space and time.

Insecticide Resistance Patterns and Mechanisms in Aedes aegypti (Diptera: Culicidae) Populations Across Abidjan, Côte d’Ivoire Reveal Emergent Pyrethroid Resistance

2021 ◽  
Author(s):  
Lucien Yao Konan ◽  
Welbeck Achille Oumbouke ◽  
Urbain Garhapié Silué ◽  
Ibrahima Zanakoungo Coulibaly ◽  
Jean-Claude Tokou Ziogba ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
Pyrethroid Resistance ◽  
Population Based ◽  
Cote D’Ivoire ◽  
Low Frequencies ◽  
Larval Habitats ◽  
Côte D'ivoire ◽  
The City

Abstract From 2008 to 2017, the city of Abidjan, Côte d’Ivoire experienced several Aedes-borne disease epidemics which required control of the vector mosquito population based on the reduction of larval habitats and insecticidal sprays for adult mosquitoes. This study was undertaken to assess the insecticide susceptibility status of Aedes aegypti (Linnaeus) in the city of Abidjan. Immature Ae. aegypti were sampled from several larval habitats within seven communes of Abidjan and reared to adults. Three to five days old F1 emerged adults were tested for susceptibility using insecticide-impregnated papers and the synergist piperonyl butoxide (PBO) following WHO bioassay guidelines. The results showed that Ae. aegypti populations from Abidjan were resistant to 0.1% propoxur, and 1% fenitrothion, with mortality rates ranging from 0% to 54.2%. Reduced susceptibility (93.4–97.5% mortality) was observed to 0.05% deltamethrin, 0.75% permethrin, 0.05% lambda-cyhalothrin, 5% malathion, and 0.8% chlorpyrifos-methyl. This reduced susceptibility varied depending on the insecticide and the collection site. The restoration of mortality when the mosquitoes were pre-exposed to the synergist PBO suggests that increased activity of oxidases could be contributing to resistance. Three kdr mutations (V410L, V1016I, and F1534C) were present in populations tested, with low frequencies for the Leu410 (0.28) and Ile1016 (0.32) alleles and high frequencies for the Cys1534 allele (0.96). These findings will be used to inform future arbovirus vector control activities in Abidjan.

scholarly journals The influence of roads on the fine-scale population genetic structure of the dengue vector Aedes aegypti (Linnaeus)

2021 ◽  
Vol 15 (2) ◽  
pp. e0009139
Author(s):  
Maria Angenica F. Regilme ◽  
Thaddeus M. Carvajal ◽  
Ann–Christin Honnen ◽  
Divina M. Amalin ◽  
Kozo Watanabe
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Aedes Aegypti ◽  
Spatial Scale ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Mosquito Control ◽  
Genetic Admixture ◽  
Fine Spatial Scale ◽  
The Road

Dengue is endemic in tropical and subtropical countries and is transmitted mainly by Aedes aegypti. Mosquito movement can be affected by human-made structures such as roads that can act as a barrier. Roads can influence the population genetic structure of Ae. aegypti. We investigated the genetic structure and gene flow of Ae. aegypti as influenced by a primary road, España Boulevard (EB) with 2000-meter-long stretch and 24-meters-wide in a very fine spatial scale. We hypothesized that Ae. aegypti populations separated by EB will be different due to the limited gene flow as caused by the barrier effect of the road. A total of 359 adults and 17 larvae Ae. aegypti were collected from June to September 2017 in 13 sites across EB. North (N1-N8) and South (S1-S5) comprised of 211 and 165 individuals, respectively. All mosquitoes were genotyped at 11 microsatellite loci. AMOVA FST indicated significant genetic differentiation across the road. The constructed UPGMA dendrogram found 3 genetic groups revealing the clear separation between North and South sites across the road. On the other hand, Bayesian cluster analysis showed four genetic clusters (K = 4) wherein each individual samples have no distinct genetic cluster thus genetic admixture. Our results suggest that human-made landscape features such as primary roads are potential barriers to mosquito movement thereby limiting its gene flow across the road. This information is valuable in designing an effective mosquito control program in a very fine spatial scale.

scholarly journals Avaliação da Presença de Aedes aegypti (Linnaeus) e Aedes albopictus (Skuse) no Município de Vassouras, RJ, Brasil

2014 ◽  
Vol 7 (2) ◽  
pp. 116-123
Author(s):  
Renata Fraga Pinheiro ◽  
Simone Pereira Alves ◽  
Alexandre Araujo Oliveira ◽  
Cleber Barreto Espindola ◽  
Marise Maleck
Keyword(s):  
Aedes Aegypti ◽  
Aedes Albopictus ◽  
The City

Este estudo teve como objetivo verificar a presença das formas imaturas de Aedes aegypti (Linnaeus) e Aedes albopictus (Skuse) no Município de Vassouras, RJ, Brasil. O levantamento foi realizado no período de junho de 2008 a maio de 2010, em sete pontos pré-determinados do município, com coletas semanais utilizando como metodologia de captura de larvas armadilhas de pneus contendo infusão de capim. Os resultados mostraram positividade de Ae. aegypti e Ae. albopictus em todos os pontos analisados e preferencialmente nos meses dezembro, janeiro e março. Evaluating the Presence of Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) in Vassouras City, RJ, Brazil Abstract. This study aimed to verify the presence of immature forms of Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) in the Vassouras City, RJ, Brazil. The survey was conducted from June 2008 to May 2010 in seven pre-determined points of the city, with weekly collections using a capturing larval methodology of the traps tires containing grass infusion. The results showed positive for Ae. aegypti and Ae. albopictus at all points analyzed and preferably in the months December, January and March.

scholarly journals Genetic structure of the mosquito Aedes aegypti in local forest and domestic habitats in Gabon and Kenya

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Siyang Xia ◽  
Luciano V. Cosme ◽  
Joel Lutomiah ◽  
Rosemary Sang ◽  
Marc F. Ngangue ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Aedes Aegypti

scholarly journals Cocirculation of two dengue virus serotypes in individual and pooled samples of Aedes aegypti and Aedes albopictus larvae

2011 ◽  
Vol 44 (1) ◽  
pp. 103-105 ◽  
Author(s):  
José Eduardo Marques Pessanha ◽  
Waleska Teixeira Caiaffa ◽  
Alzira Batista Cecilio ◽  
Felipe Campos de Melo Iani ◽  
Simone Costa Araujo ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Dengue Virus ◽  
Clinical Presentation ◽  
Rt Pcr ◽  
Virus Rna ◽  
Dengue Virus Serotypes ◽  
Belo Horizonte ◽  
The City ◽  
Pooled Samples ◽  
Virological Surveillance

INTRODUCTION: To detect dengue virus, eggs of Aedes sp were collected in the city of Belo Horizonte, Brazil, in 2007. METHODS: Egg samples were subsequently hatched and the larvae were tested for the presence of dengue virus RNA by RT-PCR. RESULTS: Among the Aedes aegypti larvae samples, 163 (37.4%) out of 435 were positive, including 32 (10.9%) of 293 individual larvae samples concomitantly positive for two serotypes. CONCLUSIONS: Virological surveillance detecting coinfected vectors in the field could represent an important strategy for understanding the numerous factors involved in the transmission and clinical presentation of dengue.

scholarly journals ZONEAMENTO DAS ÁREAS COM MAIOR PROPENSÃO PARA ADOECIMENTO PELA DENGUE NA REGIÃO INTRA-URBANA DE MONTES CLAROS (MG) A PARTIR DE VARIÁVEIS SÓCIOAMBIENTAIS E GEOESTATÍSTICA

GEOgraphia ◽  
2021 ◽  
Vol 23 (50) ◽  
Author(s):  
Diego de Sousa Ribeiro Fonseca ◽  
Ricardo Alexandrino Garcia
Keyword(s):  
Aedes Aegypti ◽  
Surface Temperature ◽  
Land Surface Temperature ◽  
Low Income ◽  
Land Surface ◽  
Descriptive Analysis ◽  
Disease Outbreaks ◽  
Predictive Variables ◽  
Analysis Application ◽  
The City

O objetivo deste estudo foi determinar as áreas que têm tido maior propensão para ocorrência de infectados pela dengue na cidade Montes Claros-MG. A metodologia consistiu na aquisição de dados relativos ao número de infectados pela dengue, por bairros, nos anos 2015, 2016 e 2017; obtenção dos Índices Breteaures sobre infestação larvária pelo Aedes aegypti nos respectivos anos; uso de imagens de satélite para estimação da temperatura de superfície (TSE); aquisição de dados sobre elevação do terreno e renda familiar. Posteriormente, foi realizada a organização do banco de dados; emprego da análise descritiva; aplicação da regressão linear múltipla e da interpolação. O uso do modelo regressivo múltiplo, StepWise progressivo, para seleção das variáveis preditoras, com maior poder para explicação dos surtos de dengue ocorridos no período, mostrou-se eficiente, permitindo que fosse operacionalizada a co-krigagem, a qual trouxe as regiões sob maior probabilidade da ocorrência de infectados pela dengue. Genericamente, a infestação larvária pelo Aedes aegypti tem acontecido na porção oeste, enquanto a infecção pela dengue tem maior propensão na porção leste da cidade.Palavras-chave: infectados; infestação larvária; temperatura de superfície; altitude; renda domiciliar. ZONNING AREAS WITH THE BIGGEST PROPENTION TO SICK PEOPLE BY DENGUE IN THE MONTES CLAROS CITY (MG) USING SOCIO ENVIRONMENTAL VARIABLES AND GEOSTATISTICS Abstract: The objective of this work was to delimitation the determinats areas with the most propention to occurrence of sick peoples by dengue in the Montes Claros city, Minas Gerais. The methodology was consists in the acquisition of databases relateded at infects numbers by dengue, by neighborhoods, betwen the years 2015, 2016 and 2017; obtaining of Breteau Index about larval infestation by Aedes aegypti in the related years; use of satelities imagery to estimation of land surface temperature (LST); acquisition of databases about land elevation and familiar income. In the next time, was realize the organization of databases; employing the descriptive analysis; application of multiple linear regretion and interpolation of files. The use of regressive model, progressing StepWise, to selection of predictive variables, with more po explication power to disease outbreaks in the period, showed efficient, and this was permited the operationabilization of the co-kriging, which brought the regions with the more probability to dengue infectation. Overall, the larval infestation by the Aedes aegypti had happened on the west side, while the infectation by dengue have been more propention on the east side of the city, two portions in different economic situations, where the western part concentrates the population with the highest income. This factor denotes the fragility of the low-income population in terms of public health and their greater lack of strategic attention.Keywords: infected; larval infestation; land surface temperature; elevation; familiar income. ZONIFICACIÓN DE UBICACIONES CON MAYOR PROPENSIÓN PARA DENGUE DENTRO DE LA CIUDAD DE MONTES CLAROS (MG) A PARTIR DE VARIABLES SOCIOAMBIENTALES Y GEOSTATISTICAS Resumen: El objetivo de este estudio fue determinar las áreas que han sido más propensas a la ocurrencia de infectados por la dengue en la ciudad Montes Claros-MG. La metodología consistió en adquirir datos sobre el número de personas infectadas por dengue, en los barrios, en los años 2015, 2016 y 2017; obtención de los Índices de Breteaures sobre infestación larvaria por Aedes aegypti en los años respectivos; uso de imágenes de satélite para estimar la temperatura de la superficie (TS); adquisición de datos sobre elevación del terreno e ingresos familiares. Posteriormente, se organizó la base de datos; se hizo uso de análisis descriptivo; aplicación de interpolación y regresión lineal múltiple. El uso del modelo regresivo múltiple, progresivo StepWise, para seleccionar las variables predictoras, con mayor poder para explicar lo fenómeno de la dengue ocurridos en el período, resultó ser eficiente, permitiendo la operacionalización de la co-kriging, lo que llevó a las regiones bajo mayor probabilidad de personas infectadas con dengue. Generalmente, la infestación de larvas por el Aedes aegypti ha ocurrido en la parte occidental, mientras que la infección por la dengue es más probable en la parte oriental de la ciudad, dos partes en situaciones económicas diferentes, donde la parte occidental concentra la población de mayores ingresos. Este factor denota la fragilidad de la población de bajos ingresos en materia de salud pública y su mayor falta de atención estratégica.Palabras Clave: infectado; infestación de larvas; temperatura de la superficie; altitud; ingresos del hogar.

scholarly journals A decade of arbovirus emergence in the temperate southern cone of South America: dengue, Aedes aegypti and climate dynamics in Córdoba, Argentina

2020 ◽  
Author(s):  
Elizabet L. Estallo ◽  
Rachel Sippy ◽  
Anna M. Stewart-Ibarra ◽  
Marta G. Grech ◽  
Elisabet M. Benitez ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Disease Transmission ◽  
Considerable Increase ◽  
Human Movement ◽  
Surveillance Study ◽  
Entomological Surveillance ◽  
Entire Study ◽  
Dengue Transmission ◽  
The City

AbstractBackgroundArgentina is located at the southern temperate range of arboviral transmission by the mosquito Aedes aegypti and has experienced a rapid increase in disease transmission in recent years. Here we present findings from an entomological surveillance study that began in Córdoba, Argentina, following the emergence of dengue in 2009.MethodsFrom 2009 to 2017, larval surveys were conducted monthly, from November to May, in 600 randomly selected households distributed across the city. From 2009 to 2013, ovitraps (n=177) were sampled weekly to monitor the oviposition activity of Ae. aegypti. We explored seasonal and interannual dynamics of entomological variables and dengue transmission. Cross correlation analysis was used to identify significant lag periods.ResultsAedes aegypti were detected over the entire study period, and abundance peaked during the summer months (January to March). We identified a considerable increase in the proportion of homes with juvenile Ae. aegypti over the study period (from 5.7% of homes in 2009-10 to 15.4% of homes in 2016-17). Aedes aegypti eggs per ovitrap and larval abundance were positively associated with temperature in the same month. Autochthonous dengue transmission peaked in April, following a peak in imported dengue cases in March; autochthonous dengue was not positively associated with vector or climate variables.ConclusionsThis longitudinal study provides insights into the complex dynamics of arbovirus transmission and vector populations in a temperate region of arbovirus emergence. Our findings suggest that Córdoba is well suited for arbovirus disease transmission, given the stable and abundant vector populations. Further studies are needed to better understand the role of regional human movement.Author summaryThere is an increasing risk of arbovirus transmission in temperate regions. Argentina is located at the southern range of dengue virus transmission by the Aedes aegypti mosquito. In the last decade, epidemics of dengue fever have emerged for the first time in the city of Córdoba, Argentina. We present the study design and findings from an entomological surveillance study in Córdoba, which began following the emergence of dengue in 2009. We found that Ae. aegypti were most abundant from January to March, followed by a peak in local dengue transmission in April. Over the study period, we noted a considerable increase in the proportion of homes with Ae. aegypti. Vector indices were positively associated with warmer temperatures, which have been increasing in this region. However, the timing of local dengue transmission appears to be driven by the appearance of imported dengue cases associated with human movement. These results highlight the important role of long term surveillance studies in areas of disease emergence.

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