#Sequencing of #ZIKV #genomes directly from Ae. aegypti and Cx. quinquefasciatus #mosquitoes collected during the 2015-16 #epidemics in #Recife (Infect Genet Evol., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Infect Genet Evol. 2020 Jan 6:104180. doi: 10.1016/j.meegid.2020.104180. [Epub ahead of print]

Sequencing of ZIKV genomes directly from Ae. aegypti and Cx. quinquefasciatus mosquitoes collected during the 2015-16 epidemics in Recife.

Paiva MHS1, Guedes DRD2, Krokovsky L2, Machado LC2, Rezende TMT2, de Morais Sobral MC2, Ayres CFJ2, Wallau GL3.

Author information: 1 Universidade Federal de Pernambuco, Caruaru, Brazil. 2 Entomology Department of the Aggeu Magalhães Institute, Oswaldo Cruz Foundation, Recife, Pernambuco, Brazil. 3 Entomology Department of the Aggeu Magalhães Institute, Oswaldo Cruz Foundation, Recife, Pernambuco, Brazil. Electronic address: gabriel.wallau@cpqam.fiocruz.br.

 

Abstract

Zika virus (ZIKV) is a negative sense RNA virus from the Flaviviridae family, which was relatively unknown until the first human epidemic in Micronesia, in 2007. Since its spread to French Polynesia and the Americas. Recife, the capital of Pernambuco state and epicenter of the Zika epidemic in Brazil, experienced a large number of microcephaly cases and other congenital abnormalities associated to the ZIKV infection from, 2015 to 16. Evidences suggest that both Aedes aegypti and Culex quinquefasciatus mosquitoes from Recife are capable of replicating and transmitting the virus. Here, we conducted high throughput sequencing of ZIKV genomes directly from Ae. aegypti and Cx. quinquefasciatus mosquitoes collected during the ZIKV epidemics in Recife, in order to investigate the variability and evolution of the virus. We obtained 11 draft ZIKV genomes derived from 5 pools from each Ae. aegypti and Cx. quinquefasciatus species. Genome coverage breadth ranged from 16 to 100% and average depth from 45 to 46,584×. Two of these genomes were obtained from pools of unfed Cx. quinquefasciatus females. Amino acid substitutions found here were not species-specific, which could indicate species specific virus adaptation. In addition, molecular clock dating estimated that ZIKV draft genomes obtained here were co-circulating in the region during the epidemics. Overall results highlight that viral mutations and even minor variants can be detected in genomes directly sequenced from mosquito samples and insights about natural viral genomic variability and viral evolution can be useful when designing tools for mosquito control programs.

Copyright © 2019. Published by Elsevier B.V.

KEYWORDS: Aedes aegypti; Arboviruses; Culex quinquefasciatus; Surveillance; ZIKV

PMID: 31918041 DOI: 10.1016/j.meegid.2020.104180

Keywords: Zika Virus; Aedes aegypti; Culex quinquefascitus; Mosquitoes; Brazil.

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#Risk of #dengue in Central #Africa: #Vector competence studies with #Aedes aegypti and Aedes albopictus (Diptera: Culicidae) populations and dengue 2 virus (PLOS Negl Trop Dis., abstract)

[Source: PLOS Neglected Tropical Diseases, full page: (LINK). Abstract, edited.]

OPEN ACCESS /  PEER-REVIEWED / RESEARCH ARTICLE

Risk of dengue in Central Africa: Vector competence studies with Aedes aegypti and Aedes albopictus (Diptera: Culicidae) populations and dengue 2 virus

Basile Kamgang , Marie Vazeille, Armel N. Tedjou, Theodel A. Wilson-Bahun, Aurélie P. Yougang, Laurence Mousson, Charles S. Wondji , Anna-Bella Failloux

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Published: December 30, 2019 / DOI: https://doi.org/10.1371/journal.pntd.0007985 / This is an uncorrected proof.

 

Abstract

Introduction

Dengue is the most important mosquito-borne diseases worldwide but was considered scarce in West-Central Africa. During the last decade, dengue outbreaks have increasingly been reported in urban foci in this region suggesting major epidemiological changes. However, in Central Africa where both vectors, Aedes aegypti and Aedes albopictus are well established, the role of each species in dengue transmission remains poorly investigated.

Methodology/Principal findings

Field-collected strains of Ae. aegypti and Ae. albopictus from different ecological settings in Central Africa were experimentally challenged with dengue 2 virus (DENV-2). Mosquitoes were analysed at 14- and 21-days post-infection. Analysis provide evidence that both Ae. aegypti and Ae. albopictus in Central Africa were able to transmit dengue virus with Ae. aegypti exhibiting a higher transmission rate. Unexpectedly, two Ae. aegypti populations from Bénoué and Maroua, in northern Cameroon, were not able to transmit DENV-2.

Conclusions/Significance

We conclude that both Ae. aegypti and Ae. albopictus are susceptible to DENV-2 and may intervene as active dengue vectors. These findings highlight the urgent need to plan a vector surveillance program and control methods against dengue vectors in Central Africa in order to prevent future outbreaks.

 

Author summary

Dengue virus (DENV) is a flavivirus mainly transmitted to humans through the bite of infected mosquitoes notably Aedes aegypti and Aedes albopictus. In Central Africa where both vectors, Ae. aegypti and Ae. albopictus are well established, the role of each species in dengue transmission remains poorly investigated. Here, we assessed the vector competence of Ae. aegypti and Ae. albopictus collected in different ecological settings in Central Africa to transmit dengue 2 virus (DENV-2). We provide evidence that both Ae. aegypti and Ae. albopictus in Central Africa were able to transmit dengue virus with Ae. aegypti exhibiting a higher transmission rate. These findings could increase the risk of dengue outbreak in the region and emphasize the need for a comprehensive vector surveillance program to prevent and preparedness for an intervention in case of outbreaks.

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Citation: Kamgang B, Vazeille M, Tedjou AN, Wilson-Bahun TA, Yougang AP, Mousson L, et al. (2019) Risk of dengue in Central Africa: Vector competence studies with Aedes aegypti and Aedes albopictus (Diptera: Culicidae) populations and dengue 2 virus. PLoS Negl Trop Dis 13(12): e0007985. https://doi.org/10.1371/journal.pntd.0007985

Editor: Duane J. Gubler, Duke-NUS GMS, SINGAPORE

Received: September 9, 2019; Accepted: December 10, 2019; Published: December 30, 2019

Copyright: © 2019 Kamgang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the manuscript.

Funding: BK was funded by the Wellcome Trust, 204862/Z/16/Z (https://wellcome.ac.uk). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Keywords: Flavivirus; Dengue fever; Africa region; Mosquitoes; Aedes aegypti; Aedes albopictus.

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Computational and experimental #insights into the #chemosensory #navigation of #Aedes aegypti #mosquito larvae (Proc Roy Soc B., abstract)

[Source: Proceedings of the Royal Society, Biological Sciences, full page: (LINK). Abstract, edited.]

Computational and experimental insights into the chemosensory navigation of Aedes aegypti mosquito larvae

Eleanor K. Lutz, Tjinder S. Grewal and Jeffrey A. Riffell

Published: 20 November 2019 / DOI: https://doi.org/10.1098/rspb.2019.1495

 

Abstract

Mosquitoes are prolific disease vectors that affect public health around the world. Although many studies have investigated search strategies used by host-seeking adult mosquitoes, little is known about larval search behaviour. Larval behaviour affects adult body size and fecundity, and thus the capacity of individual mosquitoes to find hosts and transmit disease. Understanding vector survival at all life stages is crucial for improving disease control. In this study, we use experimental and computational methods to investigate the chemical ecology and search behaviour of Aedes aegypti mosquito larvae. We first show that larvae do not respond to several olfactory cues used by adult Ae. aegypti to assess larval habitat quality, but perceive microbial RNA as a potent foraging attractant. Second, we demonstrate that Ae. aegypti larvae use chemokinesis, an unusual search strategy, to navigate chemical gradients. Finally, we use computational modelling to demonstrate that larvae respond to starvation pressure by optimizing exploration behaviour—possibly critical for exploiting limited larval habitat types. Our results identify key characteristics of foraging behaviour in an important disease vector mosquito. In addition to implications for better understanding and control of disease vectors, this work establishes mosquito larvae as a tractable model for chemosensory behaviour and navigation.

Keywords: Mosquitoes; Aedes aegypti.

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#Phylogeography and #invasion #history of #Aedes aegypti, the #Dengue and #Zika #mosquito vector in Cape Verde islands (West Africa) (Evol Appl., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Evol Appl. 2019 Aug 3;12(9):1797-1811. doi: 10.1111/eva.12834. eCollection 2019 Oct.

Phylogeography and invasion history of Aedes aegypti, the Dengue and Zika mosquito vector in Cape Verde islands (West Africa).

Salgueiro P1, Serrano C1, Gomes B1,2, Alves J3, Sousa CA1, Abecasis A1, Pinto J1.

Author information: 1 Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT) Universidade Nova de Lisboa (UNL) Lisboa Portugal. 2 Oswaldo Cruz Institute (IOC) Fundação Oswaldo Cruz (FIOCRUZ) Rio de Janeiro Brasil. 3 Direção Geral de Saúde/Instituto Nacional de Saúde Pública, Ministério da Saúde de Cabo Verde Praia Cabo Verde.

 

Abstract

Aedes-borne arboviruses have spread globally with outbreaks of vast impact on human populations and health systems. The West African archipelago of Cape Verde had its first outbreak of Dengue in 2009, at the time the largest recorded in Africa, and was one of the few African countries affected by the Zika virus epidemic. Aedes aegypti was the mosquito vector involved in both outbreaks. We performed a phylogeographic and population genetics study of A. aegypti in Cape Verde in order to infer the geographic origin and evolutionary history of this mosquito. These results are discussed with respect to the implications for vector control and prevention of future outbreaks. Mosquitoes captured before and after the Dengue outbreak on the islands of Santiago, Brava, and Fogo were analyzed with two mitochondrial genes COI and ND4, 14 microsatellite loci and five kdr mutations. Genetic variability was comparable to other African populations. Our results suggest that A. aegypti invaded Cape Verde at the beginning of the Holocene from West Africa. Given the historic importance of Cape Verde in the transatlantic trade of the 16th-17th centuries, a possible contribution to the genetic pool of the founding populations in the New World cannot be fully discarded. However, contemporary gene flow with the Americas is likely to be infrequent. No kdr mutations associated with pyrethroid resistance were detected. The implications for vector control and prevention of future outbreaks are discussed.

KEYWORDS: Aedes aegypti; Africa; Cape Verde; Dengue; Zika; phylogeography; population genetics; vector control

PMID: 31548858 PMCID: PMC6752157 DOI: 10.1111/eva.12834

Keywords: Mosquitoes; Aedes aegypti; Zika virus; Dengue fever; Cape Verde.

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#Vector #Competence: What Has #Zika Virus Taught Us? (Viruses, abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Viruses. 2019 Sep 17;11(9). pii: E867. doi: 10.3390/v11090867.

Vector Competence: What Has Zika Virus Taught Us?

Azar SR1,2,3, Weaver SC4,5,6.

Author information: 1 Department of Microbiology and Immunology, University of Texas Medical Branch, 300 University Blvd, Galveston, TX 77555, USA. srazar@utmb.edu. 2 Institute for Translational Sciences, University of Texas Medical Branch, 300 University Blvd, Galveston, TX 77555, USA. srazar@utmb.edu. 3 Institute for Human Infections and Immunity, University of Texas Medical Branch, 300 University Blvd, Galveston, TX 77555, USA. srazar@utmb.edu. 4 Department of Microbiology and Immunology, University of Texas Medical Branch, 300 University Blvd, Galveston, TX 77555, USA. sweaver@utmb.edu. 5 Institute for Translational Sciences, University of Texas Medical Branch, 300 University Blvd, Galveston, TX 77555, USA. sweaver@utmb.edu. 6 Institute for Human Infections and Immunity, University of Texas Medical Branch, 300 University Blvd, Galveston, TX 77555, USA. sweaver@utmb.edu.

 

Abstract

The unprecedented outbreak of Zika virus (ZIKV) infection in the Americas from 2015 to 2017 prompted the publication of a large body of vector competence data in a relatively short period of time. Although differences in vector competence as a result of disparities in mosquito populations and viral strains are to be expected, the limited competence of many populations of the urban mosquito vector, Aedes aegypti, from the Americas (when its susceptibility is viewed relative to other circulating/reemerging mosquito-borne viruses such as dengue (DENV), yellow fever (YFV), and chikungunya viruses (CHIKV)) has proven a paradox for the field. This has been further complicated by the lack of standardization in the methodologies utilized in laboratory vector competence experiments, precluding meta-analyses of this large data set. As the calls for the standardization of such studies continue to grow in number, it is critical to examine the elements of vector competence experimental design. Herein, we review the various techniques and considerations intrinsic to vector competence studies, with respect to contemporary findings for ZIKV, as well as historical findings for other arboviruses, and discuss potential avenues of standardization going forward.

KEYWORDS: Aedes aegypti; Flaviviruses; Zika virus; arbovirus; mosquitoes; vector competence

PMID: 31533267 DOI: 10.3390/v11090867

Keywords: Mosquitoes; Aedes aegypti; Flavivirus; Zika Virus.

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#Transgenic #Aedes aegypti #Mosquitoes Transfer #Genes into a Natural #Population (Sci Rep., abstract)

[Source: Scientific Reports, full page: (LINK). Abstract, edited.]

Transgenic Aedes aegypti Mosquitoes Transfer Genes into a Natural Population

Benjamin R. Evans, Panayiota Kotsakiozi, Andre Luis Costa-da-Silva, Rafaella Sayuri Ioshino, Luiza Garziera, Michele C. Pedrosa, Aldo Malavasi, Jair F. Virginio, Margareth L. Capurro & Jeffrey R. Powell

Scientific Reports, volume 9, Article number: 13047 (2019)

 

Abstract

In an attempt to control the mosquito-borne diseases yellow fever, dengue, chikungunya, and Zika fevers, a strain of transgenically modified Aedes aegypti mosquitoes containing a dominant lethal gene has been developed by a commercial company, Oxitec Ltd. If lethality is complete, releasing this strain should only reduce population size and not affect the genetics of the target populations. Approximately 450 thousand males of this strain were released each week for 27 months in Jacobina, Bahia, Brazil. We genotyped the release strain and the target Jacobina population before releases began for >21,000 single nucleotide polymorphisms (SNPs). Genetic sampling from the target population six, 12, and 27–30 months after releases commenced provides clear evidence that portions of the transgenic strain genome have been incorporated into the target population. Evidently, rare viable hybrid offspring between the release strain and the Jacobina population are sufficiently robust to be able to reproduce in nature. The release strain was developed using a strain originally from Cuba, then outcrossed to a Mexican population. Thus, Jacobina Ae. aegypti are now a mix of three populations. It is unclear how this may affect disease transmission or affect other efforts to control these dangerous vectors. These results highlight the importance of having in place a genetic monitoring program during such releases to detect un-anticipated outcomes.

Keywords: Genetics; Aedes aegypti; Brazil; GMOs.

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First report on the #transmission of #Zika virus by #Aedes (Stegomyia) aegypti (L.) (Diptera: Culicidae) during the 2018 Zika #outbreak in #India (Acta Trop., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Acta Trop. 2019 Aug 20:105114. doi: 10.1016/j.actatropica.2019.105114. [Epub ahead of print]

First report on the transmission of Zika virus by Aedes (Stegomyia) aegypti (L.) (Diptera: Culicidae) during the 2018 Zika outbreak in India.

Singh H1, Singh OP2, Akhtar N3, Sharma G4, Sindhania A5, Gupta N6, Valecha N7.

Author information: 1 National Institute of Malaria Research, Sector 8 Dwarka, New Delhi 110077, India. Electronic address: hspawar@rediffmail.com. 2 National Institute of Malaria Research, Sector 8 Dwarka, New Delhi 110077, India. Electronic address: singh@nimr.org.in. 3 National Institute of Malaria Research, Sector 8 Dwarka, New Delhi 110077, India. Electronic address: nasreen84akhtar@gmail.com. 4 National Institute of Malaria Research, Sector 8 Dwarka, New Delhi 110077, India. Electronic address: gunjan.sharma@gmail.com. 5 National Institute of Malaria Research, Sector 8 Dwarka, New Delhi 110077, India. Electronic address: ankita@mrcindia.org. 6 Indian Council of Medical Research, Ansari Nagar, New Delhi, 110029, India. Electronic address: ngupta@icmr.org.in. 7 National Institute of Malaria Research, Sector 8 Dwarka, New Delhi 110077, India. Electronic address: neenavalecha@gmail.com.

 

Abstract

In a recent outbreak of Zika virus (ZIKV) infection in Jaipur city (Rajasthan, India), a total of 159 cases were reported in September 2018. In order to identify vector responsible for Zika transmission, mosquitoes were collected from houses with reported Zika cases and nearby houses. A total of 108 pools containing 522 mosquitoes were tested for presence of ZIKV virus using RT-PCR and Real Time RT-PCR. We detected presence of ZIKV in three pools of Aedes (Stegomyia) aegypti (L.), out of a total of 79 pools with 383 Ae. aegypti through RT-PCR as well as real-time RT-PCR. The presence of ZIKV in Ae. aegypti was further confirmed by DNA sequencing of the partial envelope region of ZIKV. Homology search of DNA sequence revealed highest identity (100%) with a ZIKV isolate from human from the study area which support the role of Ae. aegypti acting as a ZIKV vector. All other mosquitoes (Aedes vittatus and Culex quinquefasciatus) were negative for ZIKV. None of the F1 generation mosquito pools (276 mosquitoes in 43 pools) were found positive. This is the first report of presence of ZIKV in Ae. aegypti from the Indian subcontinent.

Copyright © 2019. Published by Elsevier B.V.

KEYWORDS: Entomological surveillance; Outbreak; RT-PCR; Transmission risk

PMID: 31442386 DOI: 10.1016/j.actatropica.2019.105114

Keywords: Zika Virus; Aedes aegypti; India; Mosquitoes.

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