#Wolbachia pipientis occurs in #Aedes aegypti populations in #NM and #Florida, #USA (Ecol Evol., abstract)

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

Ecol Evol. 2019 Apr 26;9(10):6148-6156. doi: 10.1002/ece3.5198. eCollection 2019 May.

Wolbachia pipientis occurs in Aedes aegypti populations in New Mexico and Florida, USA.

Kulkarni A1, Yu W1, Jiang J1, Sanchez C1, Karna AK1, Martinez KJL1, Hanley KA1, Buenemann M2, Hansen IA1, Xue RD3, Ettestad P4, Melman S4, Duguma D5, Debboun M5, Xu J1.

Author information: 1 Biology Department New Mexico State University Las Cruces New Mexico. 2 Department of Geography New Mexico State University Las Cruces New Mexico. 3 Anastasia Mosquito Control District St. Augustine Florida. 4 New Mexico Department of Health Santa Fe New Mexico. 5 Harris County Public Health Mosquito and Vector Control Division Houston Texas.

 

Abstract

The mosquitoes Aedes aegypti (L.) and Ae. albopictus Skuse are the major vectors of dengue, Zika, yellow fever, and chikungunya viruses worldwide. Wolbachia, an endosymbiotic bacterium present in many insects, is being utilized in novel vector control strategies to manipulate mosquito life history and vector competence to curb virus transmission. Earlier studies have found that Wolbachia is commonly detected in Ae. albopictus but rarely detected in Ae. aegypti. In this study, we used a two-step PCR assay to detect Wolbachia in wild-collected samples of Ae. aegypti. The PCR products were sequenced to validate amplicons and identify Wolbachia strains. A loop-mediated isothermal amplification (LAMP) assay was developed and used for detecting Wolbachia in selected mosquito specimens as well. We found Wolbachiain 85/148 (57.4%) wild Ae. aegypti specimens from various cities in New Mexico, and in 2/46 (4.3%) from St. Augustine, Florida. Wolbachiawas not detected in 94 samples of Ae. aegypti from Deer Park, Harris County, Texas. Wolbachia detected in Ae. aegypti from both New Mexico and Florida was the wAlbB strain of Wolbachia pipientis. A Wolbachia-positive colony of Ae. aegypti was established from pupae collected in Las Cruces, New Mexico, in 2018. The infected females of this strain transmitted Wolbachia to their progeny when crossed with males of Rockefeller strain of Ae. aegypti, which does not carry Wolbachia. In contrast, none of the progeny of Las Cruces males mated to Rockefeller females were infected with Wolbachia.

KEYWORDS: Aedes aegypti; Aedes albopictus; Florida; New Mexico; Texas; Wolbachia; wAlbB

PMID: 31161026 PMCID: PMC6540660 DOI: 10.1002/ece3.5198

Keywords: Arbovirus; Mosquitoes; Aedes aegypti; Aedes albopictus; New Mexico; Florida; USA.

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On #lifestyle trends, #health and #mosquitoes: Formulating welfare levels for control of the Asian tiger mosquito in #Greece (PLoS Negl Trop Dis., abstract)

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

OPEN ACCESS /  PEER-REVIEWED / RESEARCH ARTICLE

On lifestyle trends, health and mosquitoes: Formulating welfare levels for control of the Asian tiger mosquito in Greece

Antonios Kolimenakis , Kostas Bithas, Dionysis Latinopoulos, Clive Richardson

Published: June 4, 2019 / DOI: https://doi.org/10.1371/journal.pntd.0007467 / This is an uncorrected proof.

 

Abstract

The expansion of urban ecosystems and climate change, both outcomes of massive lifestyle changes, contribute to a series of side effects such as environmental deterioration, spread of diseases, increased greenhouse gas emissions and introduction of invasive species. In the case of the Athens metropolitan area, an invasive mosquito species—the Asian tiger mosquito (Aedes albopictus)–has spread widely in the last decade. This spread is favoured within urban environments and is also affected by changing climatic trends. The Asian tiger mosquito is accompanied by risks of mosquito-borne diseases, greater nuisance levels, and increased expenses incurring for its confrontation. The main aims of this paper are (i) to estimate the various costs associated with their control of this invasive species, as well as its health and nuisance impacts, (ii) to evaluate the level of citizens’ well-being from averting these impacts and (iii) to record citizens’ and experts’ perceptions regarding alternative control measures. Evidence shows that experts tend to place a high value on mosquito control when associated with serious health risks, while citizens are more sensitive and concerned about the environmental impacts of control methods. The synthesis of results produced by the current study could act as a preliminary guide for the estimation of societal welfare from the confrontation of similar problems in the context of a complex ecosystem.

 

Author summary

This paper is based on several years’ collaboration among researchers from various disciplines, key health policy makers and stakeholders in an attempt to evaluate the economic dimensions related to the presence of the Asian Tiger Mosquito (Aedes albopictus) and the challenges of tackling mosquito-borne disease outbreaks in Greece and Southern Europe. Similar studies have been conducted and continue to be published in Europe and the USA examining the socioeconomic benefit from the implementation of relevant control and prevention strategies. These studies conclude that there are significant benefits related both to the reduction of nuisance levels and the reduction of the health risks posed by various mosquito species. In our case, the application of an updated economic analysis on the effectiveness of relevant public control and prevention programs provides essential information for public health decision-making, bearing in mind the significant restructuring of the public sector and the fiscal crisis apparent in the European South.

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Citation: Kolimenakis A, Bithas K, Latinopoulos D, Richardson C (2019) On lifestyle trends, health and mosquitoes: Formulating welfare levels for control of the Asian tiger mosquito in Greece. PLoS Negl Trop Dis 13(6): e0007467. https://doi.org/10.1371/journal.pntd.0007467

Editor: Olaf Horstick, University of Heidelberg, GERMANY

Received: October 2, 2018; Accepted: May 14, 2019; Published: June 4, 2019

Copyright: © 2019 Kolimenakis 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 and its Supporting Information files.

Funding: Part of this research has been co-financed by the European Union (EU Environmental Funding Programme LIFE+ Environment Policy and Governance) and Greek national funds through the LIFE CONOPS project “Development & demonstration of management plans against—the climate change enhanced—invasive mosquitoes in S. Europe” (LIFE12ENV/GR/000466). 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: Climate change; Mosquitoes; Aedes albopictus; Society; Poverty; Greece.

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#Aedes albopictus is a competent #vector of #Zika virus: A meta-analysis (PLoS One, abstract)

[Source: PLoS One, full page: (LINK). Abstract, edited.]

OPEN ACCESS /  PEER-REVIEWED / RESEARCH ARTICLE

Aedes albopictus is a competent vector of Zika virus: A meta-analysis

Benjamin A. McKenzie , Alan E. Wilson, Sarah Zohdy

Published: May 21, 2019 / DOI: https://doi.org/10.1371/journal.pone.0216794

 

Abstract

Background

Much work has been done in recent years to determine the vector competence of Aedes albopictus (Skuse) for Zika virus (ZIKV). If competent, Ae. albopictus could become an important vector in the spread of ZIKV to areas which until now have been considered safe from the virus. Despite much speculation about Ae. albopictus’ competence for ZIKV, there have been, to date, no quantitative syntheses of Ae. albopictus’ competence, nor have the potentially confounding differences between studies been addressed.

Methodology/ principle findings

This study represents a quantitative meta-analysis of the literature surrounding this topic by examining infection rates (IR) and transmission rates (TR) among sample populations of Ae. albopictus at 7 and 14 days post infection (dpi) across 15 journal articles comprising 23 studies. Our analyses examined potentially confounding variables in the studies contained therein, including: geographic origin of viral strain or mosquito population tested, whether sympatry of the tested viral strain and mosquito population was important, and freshness of blood meal. Our results suggest 1) Ae albopictus is a competent vector for ZIKV and 2) that origin of Ae. albopictus population and origin of viral strain had significant effects on the competence of Ae. albopictus to transmit ZIKV.

Conclusions/ significance

These results indicate a need to further explore the effects of methodology on vector competence studies and to examine in more detail the geographic variation in the competence of Ae. albopictus for ZIKV as well as the underlying causes of said variation. The ability of Ae. albopictus to carry and transmit ZIKV also points to a need to create new vector control strategies in case of a ZIKV outbreak in an area where Ae. albopictus is prominent. Finally, this study represents a potential template for future meta-analyses in the field of vector competence, where this type of study has been under-utilized despite the abundance of relevant studies.

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Citation: McKenzie BA, Wilson AE, Zohdy S (2019) Aedes albopictus is a competent vector of Zika virus: A meta-analysis. PLoS ONE 14(5): e0216794. https://doi.org/10.1371/journal.pone.0216794

Editor: Luciano Andrade Moreira, Centro de Pesquisas René Rachou, BRAZIL

Received: November 20, 2018; Accepted: April 29, 2019; Published: May 21, 2019

Copyright: © 2019 McKenzie 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 as a supplementary data table and cited references.

Funding: Funding was provided by the United States Department of Agriculture to AW and SZ. 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: Zika Virus; Aedes albopictus; Mosquitoes.

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Evidence for #infection but not #transmission of #Zika virus by #Aedes albopictus (Diptera: Culicidae) from #Spain (Parasit Vectors., abstract)

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

Parasit Vectors. 2019 May 3;12(1):204. doi: 10.1186/s13071-019-3467-y.

Evidence for infection but not transmission of Zika virus by Aedes albopictus (Diptera: Culicidae) from Spain.

Hernández-Triana LM1, Barrero E2, Delacour-Estrella S3, Ruiz-Arrondo I4, Lucientes J3, Fernández de Marco MDM2, Thorne L2, Lumley S5, Johnson N2,6, Mansfield KL2, Fooks AR2,7.

Author information: 1 Wildlife Zoonoses and Vector-borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey, KT15 3NB, UK. luis.hernandez-triana@apha.gov.uk. 2 Wildlife Zoonoses and Vector-borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey, KT15 3NB, UK. 3 Department of Animal Pathology, Faculty of Veterinary Medicine, University of Zaragoza, Zaragoza, Spain. 4 Center for Rickettsiosis and Vector-Borne Diseases Group, Hospital Universitario San Pedro-CIBIR, Logroño, Spain. 5 Public Health England, Porton Down, Salisbury, SP4 0JG, UK. 6 Faculty of Health and Medicine, University of Surrey, Guildford, Surrey, GU27XH, UK. 7 Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK.

 

Abstract

BACKGROUND:

A number of mosquito-borne viruses such as dengue virus (DENV), Usutu virus (USUV), West Nile virus (WNV) are autochthonously transmitted in Europe and six invasive mosquito species have been detected in this temperate region. This has increased the risk for the emergence of further mosquito-borne diseases. However, there is a paucity of information on whether European populations of invasive mosquito species are competent to transmit arboviruses. In this study, the susceptibility of Aedes albopictus originating from Spain and a laboratory-adapted colony of Aedes aegypti, was assessed for infection with, and transmission of Zika virus (ZIKV). Vertical transmission in both species was also assessed.

METHODS:

Aedes albopictus colonised from eggs collected in Spain and an existing colony of Ae. aegypti were fed infectious blood meals containing ZIKV (Polynesian strain) at 1.6 × 107 PFU/ml. Blood-fed mosquitoes were separated and maintained at 20 °C or 25 °C. Legs, saliva and bodies were sampled from specimens at 7, 14 and 21 days post-infection (dpi) in order to determine infection, dissemination and transmission rates. All samples were analysed by real-time RT-PCR using primers targeting the ZIKV NS1 gene.

RESULTS:

At 14 dpi and 21 dpi, ZIKV RNA was detected in the bodies of both species at both temperatures. However, live virus only was detected in the saliva of Ae. aegypti at 25 °C with a transmission rate of 44%. No evidence for virus expectoration was obtained for Ae. albopictus under any condition. Notably, ZIKV RNA was not detectable in the saliva of Ae. aegypti at 20 °C after 21 days. No vertical transmission of ZIKV was detected in this study.

CONCLUSIONS:

Experimental infection of Ae. albopictus colonized from Spain with ZIKV did not result in expectoration of virus in saliva in contrast to results for Ae. aegypti. No evidence of vertical transmission of virus was observed in this study. This suggests that this strain of Ae. albopictus is not competent for ZIKV transmission under the conditions tested.

KEYWORDS: Aedes aegypti; Aedes albopictus; Spain; Vector competence; Zika virus

PMID: 31053164 DOI: 10.1186/s13071-019-3467-y

Keywords: Zika Virus; Mosquitoes; Aedes aegytpi; Aedes albopictus; Spain.

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#Arboviral #screening of invasive #Aedes species in northeastern #Turkey: #WNV circulation and detection of insect-only viruses (PLoS Negl Trop Dis., abstract)

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

OPEN ACCESS /  PEER-REVIEWED / RESEARCH ARTICLE

Arboviral screening of invasive Aedes species in northeastern Turkey: West Nile virus circulation and detection of insect-only viruses

Mustafa M. Akıner, Murat Öztürk, Aykut Buğra Başer, Filiz Günay, Sabri Hacıoğlu, Annika Brinkmann, Nergis Emanet, Bülent Alten, Aykut Özkul, Andreas Nitsche, Yvonne-Marie Linton, Koray Ergünay

Published: May 6, 2019 / DOI: https://doi.org/10.1371/journal.pntd.0007334 / This is an uncorrected proof.

 

Abstract

Background

The recent reports of Aedes aegypti and Ae. albopictus populations in Turkey, in parallel with the territorial expansion identified in several surrounding countries, have raised concerns about the establishment and re-establishment of these invasive Aedes mosquitoes in Turkey. This cross-sectional study was performed to detect Aedes aegypti and Ae. albopictus in regions of recent incursions, and screen for viral pathogens known to be transmitted elsewhere by these species.

Methodology

Mosquitoes were collected at several locations in Artvin, Rize and Trabzon provinces of the Black Sea region during 2016–2017, identified morphologically, pooled and analyzed via generic or specific nucleic acid amplification assays. Viruses in positive pools were identified by product sequencing, cell culture inoculation and next generation sequencing (NGS) in selected specimens.

Principal findings

The study group comprised 791 specimens. Aedes albopictus was the most abundant species in all locations (89.6%), followed by Ae. aegypti (7.8%) and Culex pipiens (2.5%). Mosquitoes were screened for viruses in 65 pools where fifteen (23.1%) were reactive. The infecting strains was identified as West Nile virus (WNV) in 5 pools (7.7%) with Ae. albopictus or Cx. pipiensmosquitoes. The obtained WNV sequences phylogenetically grouped with local and global lineage 1 clade 1a viruses. In 4 (6.2%) and 6 (9.2%) pools, respectively, cell fusing agent virus (CFAV) and Aedes flavivirus (AEFV) sequences were characterized. NGS provided a near-complete AEFV genome in a pool of Ae. albopictus. The strain is provisionally called “AEFV-Turkey”, and functional analysis of the genome revealed several conserved motifs and regions associated with virus replication. Merida-like virus Turkey (MERDLVT), a recently-described novel rhabdovirus, was also co-detected in a Cx. pipiens pool also positive for WNV.

Conclusions/Significance

Invasive Aedes mosquitoes are established in certain locations of northeastern Turkey. Herein we conclusively show the role of these species in WNV circulation in the region. Biosurveillance is imperative to monitor the spread of these species further into Asia Minor and to detect possible introduction of pathogens.

 

Author summary

Mosquitoes can transmit viruses to susceptible humans during blood-feeding. The presence and establishment of particular mosquito species within a region is the prerequisite for the introduction and emergence of the diseases transmitted by that species. Aedes mosquitoes transmit dengue and yellow fever, as well as recently-emergent chikungunya and Zika viruses to susceptible humans. Mosquitoes were collected in the Black Sea region of Anatolia, NE Turkey, where invasive Aedes mosquitoes have recently encroached, and specimens were screened for a variety of viruses. We observed particular Aedes species that are associated with disease transmission, suggesting that these species have been established in the region. We did not detect dengue, yellow fever, chikungunya or Zika viruses, but West Nile virus was found in several pools of these invasive species. Moreover, we detected a number of related viruses that exclusively infect mosquitoes, identified for the first time in Anatolia. Using advanced sequencing technologies, the near-complete genome of a new Aedes flavivirus (AEFV-Turkey) was achieved.

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Citation: Akıner MM, Öztürk M, Başer AB, Günay F, Hacıoğlu S, Brinkmann A, et al. (2019) Arboviral screening of invasive Aedes species in northeastern Turkey: West Nile virus circulation and detection of insect-only viruses. PLoS Negl Trop Dis 13(5): e0007334. https://doi.org/10.1371/journal.pntd.0007334

Editor: Pattamaporn Kittayapong, Faculty of Science, Mahidol University, THAILAND

Received: January 3, 2019; Accepted: March 26, 2019; Published: May 6, 2019

This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

Data Availability: The nucleotide sequences characterized in this study are deposited and can be accessed at the GenBank via the following accession numbers: MF361262, MF361264, MF361265, MF361263, MF361267, MF361268, MK251047, MK251048, MK251049, MK251050, MK251051, MK251052, MK251053, MK251054, MK251055 and MK251056. All remaining data are within the paper and its Supporting Information files.

Funding: This study was supported in part by the Armed Forces Health Surveillance Board, Global Emerging Infections Surveillance and Response System (AFHSB-GEIS), United States of America (FY18 award P0034_18_WR (PI: Yvonne-Marie Linton) under US Army subcontract W911QY-16-C-0160). BA and FG were also included in AIM-COST. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The material to be published reflects the views of the authors and should not be construed to represent those of the US Department of the Army or the US Department of Defense.

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

Keywords: Flavivirus; Rhabdovirus; Mosquitoes; WNV; Aedes albopictus; Culex spp.; Turkey; Merida-like Turkey virus.

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#Vector #competence of #Australian #Aedes aegypti and Aedes albopictus for an #epidemic strain of #Zika virus (PLoS Negl Trop Dis., abstract)

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

OPEN ACCESS /  PEER-REVIEWED / RESEARCH ARTICLE

Vector competence of Australian Aedes aegypti and Aedes albopictus for an epidemic strain of Zika virus

R. Leon E. Hugo , Liesel Stassen , Jessica La, Edward Gosden, O’mezie Ekwudu, Clay Winterford, Elvina Viennet, Helen M. Faddy, Gregor J. Devine, Francesca D. Frentiu

Published: April 4, 2019 / DOI: https://doi.org/10.1371/journal.pntd.0007281 / This is an uncorrected proof.

 

Abstract

Background

Recent epidemics of Zika virus (ZIKV) in the Pacific and the Americas have highlighted its potential as an emerging pathogen of global importance. Both Aedes (Ae.) aegypti and Ae. albopictus are known to transmit ZIKV but variable vector competence has been observed between mosquito populations from different geographical regions and different virus strains. Since Australia remains at risk of ZIKV introduction, we evaluated the vector competence of local Ae. aegypti and Ae. albopictus for a Brazilian epidemic ZIKV strain. In addition, we evaluated the impact of daily temperature fluctuations around a mean of 28°C on ZIKV transmission and extrinsic incubation period.

Methodology/Principal findings

Mosquitoes were orally challenged with a Brazilian ZIKV strain (8.8 log CCID50/ml) and maintained at either 28°C constant or fluctuating temperature conditions. At 3, 7 and 14 days post-infection (dpi), ZIKV RNA copies were quantified in mosquito bodies, as well as wings and legs, using qRT-PCR, while virus antigen in saliva (a proxy for transmission) was detected using a cell culture ELISA. Despite high body and disseminated infection rates in both vectors, the transmission rates of ZIKV in saliva of Ae. aegypti (50–60%) were significantly higher than in Ae. albopictus (10%) at 14 dpi. Both species supported a high viral load in bodies, with no significant differences between constant and fluctuating temperature conditions. However, a significant difference in viral load in wings and legs between species was observed, with higher titres in Ae. aegypti maintained at constant temperature conditions. For ZIKV transmission to occur in Ae. aegypti, a disseminated virus load threshold of 7.59 log10 copies had to be reached.

Conclusions/Significance

Australian Ae. aegypti are better able to transmit a Brazilian ZIKV strain than Ae. albopictus. The results are in agreement with the global consensus that Ae. aegypti is the major vector of ZIKV.

 

Author summary

Zika virus (ZIKV) is a mosquito-borne pathogen that generally causes a mild febrile illness but mostly remains asymptomatic in 50–80% of infections. Infection during pregnancy can cause congenital malformations, notably microcephaly. In adults, it can cause Guillain-Barré syndrome. The recent ZIKV epidemic in the Americas has been linked to the urban vector Aedes aegypti. The presence of the species in Australia makes the region vulnerable to emerging mosquito-borne viruses. A mosquito’s competence to transmit a pathogen will depend on both the virus and vector strains. Here, we determine the vector competence of Australian Ae. aegypti and Ae. albopictus mosquitoes for a ZIKV epidemic strain, originating from the epicentre of the Brazilian outbreak, under constant and fluctuating temperatures that simulate field environments in Australia. Our results demonstrate that, although both species were susceptible to ZIKV infection, Ae. aegypti is more likely to transmit virus. Our results may aid in the formulation of public health strategies to mitigate the threat of ZIKV.

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Citation: Hugo RLE, Stassen L, La J, Gosden E, Ekwudu O, Winterford C, et al. (2019) Vector competence of Australian Aedes aegypti and Aedes albopictus for an epidemic strain of Zika virus. PLoS Negl Trop Dis 13(4): e0007281. https://doi.org/10.1371/journal.pntd.0007281

Editor: Lyric C. Bartholomay, University of Wisconsin Madison, UNITED STATES

Received: October 22, 2018; Accepted: March 5, 2019; Published: April 4, 2019

Copyright: © 2019 Hugo 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 and its Supporting Information files.

Funding: Funding was provided by the Australia National Health and Medical Research Council (NHMRC) grant number APP1125317 to FDF and GJD, an Australian Infectious Diseases seed grant “Zika virus vector biology, diagnostics and vaccines” (Pls Young, Hall and Devine), and a donation from John and Elizabeth Hunter. Australian governments fund the Australian Red Cross Blood Service to provide blood, blood products and services to the Australian community. 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: Zika Virus; Mosquitoes; Aedes aegypti; Aedes albopictus; Australia.

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Limited #risk of #Zika virus #transmission by five #Aedes albopictus #populations from #Spain (Parasit Vectors., abstract)

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

Parasit Vectors. 2019 Mar 29;12(1):150. doi: 10.1186/s13071-019-3359-1.

Limited risk of Zika virus transmission by five Aedes albopictus populations from Spain.

González MA1,2, Pavan MG2, Fernandes RS2, Busquets N3, David MR2, Lourenço-Oliveira R2,4, García-Pérez AL1, Maciel-de-Freitas R5,6.

Author information: 1 NEIKER-Instituto Vasco de Investigación y Desarrollo Agrario, Derio, Bizkaia, Spain. 2 Laboratório de Mosquitos Transmissores de Hematozoários, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/ FIOCRUZ), Rio de Janeiro, Brazil. 3 IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain. 4 Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil. 5 Laboratório de Mosquitos Transmissores de Hematozoários, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/ FIOCRUZ), Rio de Janeiro, Brazil. freitas@ioc.fiocruz.br. 6 Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil. freitas@ioc.fiocruz.br.

 

Abstract

BACKGROUND:

Aedes albopictus, the Asian tiger mosquito, is an exotic invasive species in Europe. It has substantial public health relevance due to its potential role in transmitting several human pathogens. Out of the European countries, Spain has one of the highest risk levels of autochthonous arbovirus transmission due to both the high density of Ae. albopictus and the extensive tourist influx from vector-endemic areas. This study aims to investigate the susceptibility of five Ae. albopictus populations from mainland Spain and the Balearic Islands to a Brazilian Zika virus (ZIKV) strain.

METHODS:

The F1 generation of each Ae. albopictus population was orally challenged with a ZIKV-infected blood meal (1.8 × 106 PFU/ml). At 7 and 14 days post-infection (dpi), mosquito bodies (thorax and abdomen) and heads were individually analysed through RT-qPCR to determine the infection rate (IR) and dissemination rate (DR), respectively. The saliva of infected mosquitoes was inoculated in Vero cells and the transmission rate was assessed by plaque assay or RT-qPCR on ~33 individuals per population.

RESULTS:

The IR and DR ranged between 12-88%, and 0-60%, respectively, suggesting that ZIKV is capable of crossing the midgut barrier. Remarkably, no infectious viral particle was found in saliva samples, indicating a low ability of ZIKV to overcome the salivary gland barrier. A subsequent assay revealed that a second non-infective blood meal 48 h after ZIKV exposure did not influence Ae. albopictus vector competence.

CONCLUSIONS:

The oral experimental ZIKV infections performed here indicate that Ae. albopictus from Spain become infected and disseminate the virus through the body but has a limited ability to transmit the Brazilian ZIKV strain through biting. Therefore, the results suggest a limited risk of autochthonous ZIKV transmission in Spain by Ae. albopictus.

KEYWORDS: Aedes albopictus; Plaque assay; RT-qPCR; Spanish populations; Vector competence; Viral copies; Zika virus

PMID: 30922370 DOI: 10.1186/s13071-019-3359-1

Keywords: Zika Virus; Aedes albopictus; Spain.

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