#Vertical #Transmission of #Zika Virus (Flaviviridae, #Flavivirus) in #Amazonian #Aedes aegypti (Diptera: Culicidae) Delays Egg Hatching and Larval Development of Progeny (J Med Entomol., abstract)

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

J Med Entomol. 2019 Jul 6. pii: tjz110. doi: 10.1093/jme/tjz110. [Epub ahead of print]

Vertical Transmission of Zika Virus (Flaviviridae, Flavivirus) in Amazonian Aedes aegypti (Diptera: Culicidae) Delays Egg Hatching and Larval Development of Progeny.

Chaves BA1,2, Junior ABV1, Silveira KRD3, Paz ADC1, Vaz EBDC1, Araujo RGP3, Rodrigues NB3, Campolina TB3, Orfano ADS3, Nacif-Pimenta R3, Villegas LEM3, Melo FF4, Silva BM5, Monteiro WM1,2, Guerra MDGVB1,2, Lacerda MVG1,6, Norris DE7, Secundino NFC3, Pimenta PFP1,3.

Author information: 1 Tropical Medicine Foundation Dr. Heitor Vieira Dourado, Manaus, Amazonas, Brazil. 2 Amazonas State University, Minas Gerais, Belo Horizonte, Brazil. 3 Laboratory of Medical Entomology, Rene Rachou Research Institute – FIOCRUZ, Minas Gerais, Belo Horizonte, Brazil. 4 Multidisciplinary Health Institute, Federal University of Bahia, Bahia, Brazil. 5 Department of Biological Sciences, Federal University of Ouro Preto, Minas Gerais, Ouro Preto, Brazil. 6 Leonidas and Maria Deane Research institute – FIOCRUZ, Amazonas, Brazil. 7 The Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD.



Zika virus (ZIKV) has emerged as a globally important arbovirus and has been reported from all states of Brazil. The virus is primarily transmitted to humans through the bite of an infective Aedes aegypti (Linnaeus, 1762) or Aedes albopictus (Skuse, 1895). However, it is important to know if ZIKV transmission also occurs from Ae. aegypti through infected eggs to her offspring. Therefore, a ZIKV and dengue virus (DENV) free colony was established from eggs collected in Manaus and maintained until the third-fourth generation in order to conduct ZIKV vertical transmission (VT) experiments which used an infectious bloodmeal as the route of virus exposure. The eggs from ZIKV-infected females were allowed to hatch. The resulting F1 progeny (larvae, pupae, and adults) were quantitative polymerase chain reaction (qPCR) assayed for ZIKV. The viability of ZIKV vertically transmitted to F1 progeny was evaluated by cultivation in C6/36 cells. The effects of ZIKV on immature development of Ae. aegypti was assessed and compared with noninfected mosquitoes. AmazonianAe. aegypti were highly susceptible to ZIKV infection (96.7%), and viable virus passed to their progeny via VT. Moreover, eggs from the ZIKV-infected mosquitoes had a significantly lower hatch rate and the slowest hatching. In addition, the larval development period was slower when compared to noninfected, control mosquitoes. This is the first study to illustrate VT initiated by oral infection of the parental population by using mosquitoes, which originated from the field and a ZIKV strain that is naturally circulating in-country. Additionally, this study suggests that ZIKV present in the Ae. aegypti can modify the mosquito life cycle. The data reported here suggest that VT of ZIKV to progeny from naturally infected females may have a critical epidemiological role in the dissemination and maintenance of the virus circulating in the vector.

© The Author(s) 2019. Published by Oxford University Press on behalf of Entomological Society of America.

KEYWORDS: Aedes aegypti ; Zika virus; fitness cost; vertical transmission

PMID: 31278737 DOI: 10.1093/jme/tjz110

Keywords: Flavivirus; Zika Virus; Aedes aegypti.



Natural #Vertical #Transmission of #Zika Virus in #Larval #Aedes aegypti Populations, Morelos, #Mexico (Emerg Infect Dis., abstract)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]

Volume 25, Number 8—August 2019 / Research

Natural Vertical Transmission of Zika Virus in Larval Aedes aegypti Populations, Morelos, Mexico

Mónica Izquierdo-Suzán, Selene Zárate, Jesús Torres-Flores, Fabián Correa-Morales, Cassandra González-Acosta, Edgar E. Sevilla-Reyes, Rosalia Lira, Sofía L. Alcaraz-Estrada, and Martha Yocupicio-Monroy

Author affiliations: Universidad Autónoma de la Ciudad de Mexico, Mexico City, Mexico (M. Izquierdo-Suzán, S. Zárate, M. Yocupicio-Monroy); Instituto Politécnico Nacional, Mexico City (J. Torres-Flores); Centro Nacional de Programas Preventivos y Control de Enfermedades, Mexico City (F. Correa-Morales, C. González-Acosta); Instituto Nacional de Enfermedades Respiratorias. Mexico City (E.E. Sevilla-Reyes); Instituto Mexicano del Seguro Social, Mexico City (R. Lira); Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado, Mexico City (S.L. Alcaraz-Estrada)



We characterized natural vertical transmission of Zika virus in pools of Aedes aegypti larvae hatched from eggs collected in Jojutla, Morelos, Mexico. Of the 151 pools analyzed, 17 tested positive for Zika virus RNA; infectious Zika virus was successfully isolated from 1 of the larvae pools (31N) in C6/36 cells. Real-time quantitative PCR and indirect immunofluorescence assays confirmed the identity of the isolate, named Zika virus isolate 31N; plaque assays in Vero cells demonstrated the isolate’s infectivity in a mammalian cell line. We obtained the complete genome of Zika virus isolate 31N by next-generation sequencing and identified 3 single-nucleotide variants specific to Zika virus isolate 31N using the meta-CATS tool. These results demonstrate the occurrence of natural vertical transmission of Zika virus in wild Ae. aegypti mosquitoes and suggest that this transmission mode could aid in the spread and maintenance of Zika virus in nature.

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


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

[Source: Evolutionary Applications, full page: (LINK). Abstract, edited.]


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

Patrícia Salgueiro,  Célia Serrano,  Bruno Gomes,  Joana Alves,  Carla A. Sousa,  Ana Abecasis, João Pinto

First published: 20 June 2019 / DOI:  https://doi.org/10.1111/eva.12834

This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi:10.1111/eva.12834



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.

This article is protected by copyright. All rights reserved.

Keywords: Mosquitoes: Arbovirus; Zika virus; Dengue Fever; Cape Verde; Evolution; Aedes aegypti.


The #effect of #global #change on #mosquito-borne #disease (Lancet Infect Dis., abstract)

[Source: The Lancet Infectious Diseases, full page: (LINK). Abstract, edited.]

The effect of global change on mosquito-borne disease

Lydia H V Franklinos, MSc, Prof Kate E Jones, PhD, David W Redding, PhD, Prof Ibrahim Abubakar, PhD

Published: June 18, 2019 / DOI: https://doi.org/10.1016/S1473-3099(19)30161-6



More than 80% of the global population is at risk of a vector-borne disease, with mosquito-borne diseases being the largest contributor to human vector-borne disease burden. Although many global processes, such as land-use and socioeconomic change, are thought to affect mosquito-borne disease dynamics, research to date has strongly focused on the role of climate change. Here, we show, through a review of contemporary modelling studies, that no consensus on how future changes in climatic conditions will impact mosquito-borne diseases exists, possibly due to interacting effects of other global change processes, which are often excluded from analyses. We conclude that research should not focus solely on the role of climate change but instead consider growing evidence for additional factors that modulate disease risk. Furthermore, future research should adopt new technologies, including developments in remote sensing and system dynamics modelling techniques, to enable a better understanding and mitigation of mosquito-borne diseases in a changing world.

Keywords: Arbovirus; Mosquitoes; Emerging Diseases; Climate Change.


#Vector competence of #Aedes aegypti for different strains of #Zika virus in #Argentina (PLoS Negl Trop Dis., abstract)

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


Vector competence of Aedes aegypti for different strains of Zika virus in Argentina

Melisa Berenice Bonica  , Silvina Goenaga  , María Laura Martin, Mariel Feroci, Victoria Luppo, Evangelina Muttis, Cintia Fabbri, María Alejandra Morales, Delia Enria, María Victoria Micieli , Silvana Levis

Published: June 12, 2019 / DOI: https://doi.org/10.1371/journal.pntd.0007433



The importance of Zika virus (ZIKV) has increased noticeably since the outbreak in the Americas in 2015, when the illness was associated with congenital disorders. Although there is evidence of sexual transmission of the virus, the mosquito Aedes aegypti is believed to be the main vector for transmission to humans. This species of mosquito has not only been found naturally infected with ZIKV, but also has been the subject of study in many vector competence assays that employ different strains of ZIKV around the world. In Argentina, the first case was reported in February 2016 and a total of 278 autochthonous cases have since been confirmed, however, ZIKV virus has not been isolated from any mosquito species yet in Argentina. In order to elucidate if Argentinian Ae. aegypti populations could be a possible vector of ZIKV, we conducted vector competence studies that involved a local strain of ZIKV from Chaco province, and a Venezuelan strain obtained from an imported case. For this purpose, Ae. aegypti adults from the temperate area of Argentina (Buenos Aires province) were fed with infected blood. Body, legs and saliva were harvested and tested by plaque titration on plates of Vero cells for ZIKV at 7, 11 and 14 days post infection (DPI) in order to calculate infection, transmission, and dissemination rates, respectively. Both strains were able to infect mosquitoes at all DPIs, whereas dissemination and transmission were observed at all DPIs for the Argentinian strain but only at 14 DPI for the Venezuelan strain. This study proves the ability of Ae. aegypti mosquitoes from Argentina to become infected with two different strains of ZIKV, both belonging to the Asian lineage, and that the virus can disseminate to the legs and salivary glands.


Author summary

Zika virus is a flavivirus transmitted by mosquitoes, isolated for the first time in the Ziika Forest in Uganda in 1947 from a rhesus macaque monkey. The disease is usually asymptomatic, but sometimes it causes a mild illness that comes with fever, rash, joint pain, and conjunctivitis. The World Health Organization focused the attention on this virus after the outbreak in the Americas, when the virus was linked to microcephaly and serious neurological diseases, including Guillain-Barré syndrome. Aedes aegypti was incriminated as the main vector of the virus as it was found both naturally and experimentally infected. This mosquito species was declared eradicated in Argentina by 1970 but re-emerged in 1989. Recent studies found a peculiarity in the genetics of Argentinian Ae. aegypti populations that consists in a combination between both subspecies: Ae. aegypti formosus and Ae. aegypti aegypti. Our study tries to elucidate if Ae. aegypti from Argentina are able to transmit the virus in order to add these mosquitoes to the list of possible vectors of ZIKV and, in future prospect, orient to fight the virus by controlling the vector.


Citation: Bonica MB, Goenaga S, Martin ML, Feroci M, Luppo V, Muttis E, et al. (2019) Vector competence of Aedes aegypti for different strains of Zika virus in Argentina. PLoS Negl Trop Dis 13(6): e0007433. https://doi.org/10.1371/journal.pntd.0007433

Editor: Paulo Pimenta, Fundaçao Oswaldo Cruz, BRAZIL

Received: December 11, 2018; Accepted: April 15, 2019; Published: June 12, 2019

Copyright: © 2019 Bonica 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: MBB, EM and MVM received funds from the National Agency for the Promotion of Science and Technology of Argentina (ANPCYT) (PICT 2015-0665). 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; Argentina.


Vector #Mosquito #Ecology and Japanese #Encephalitis Virus Genotype III Strain Detection from #Culex tritaeniorhynchus and #Pig in Huaihua, #China (Vector Borne Zoo Dis., abstract)

[Source: Vector Borne and Zoonotic Diseases, full page: (LINK). Abstract, edited.]

Vector Mosquito Ecology and Japanese Encephalitis Virus Genotype III Strain Detection from Culex tritaeniorhynchus and Pig in Huaihua, China

Chen Chen, Teng Zhao, Yuting Jiang, Chunxiao Li, Gang Wang, Jian Gao, Yande Dong, Dan Xing, Xiaoxia Guo, and Tongyan Zhao

Published Online: 10 Jun 2019 / DOI: https://doi.org/10.1089/vbz.2019.2453



The Japanese encephalitis virus (JEV), a mosquito-borne zoonotic pathogen, is the major cause of viral encephalitis worldwide. An investigation of mosquito species diversity, JEV infection rate, and seasonal population fluctuations of Culex tritaeniorhynchus in Huaihua County, Hunan Province, China, revealed the distribution of vector mosquito populations and genotypes and molecular characteristics of current, common JEV strains in this region. Research on mosquito species diversity in different habitats in Huaihua revealed that local community composition was relatively simple, including five species from four genera (two Culex spp., one Anopheles sp., one Aedes sp., and one Armigeres sp.). Cx. tritaeniorhynchuswas clearly the dominant species comprising 94.2–98.6% of all specimens and was always the most common species captured in paddy fields, pigpens, and human dwellings. The seasonal abundance of Cx. tritaeniorhynchus was relatively even, with a single seasonal peak in late August. Two Huaihua JEV strains isolated from the mosquito and pig were highly congruent. The genetic affinities were determined by analyzing capsid/premembrane (C/PrM) and envelope (E) gene variation. The results showed that they were of genotype III and most closely related to the live, attenuated vaccine strains SAl4-14-2 and SA14 and JaGAr01. The Huaihua E protein shares high similarity (mosquito 98.8% and pig 97.6%) at the nucleotide level with the SA14-14-2 vaccine. Although we found that the E gene sequences of the Huaihua JEV mosquito strain and pig strain have 11 and 15 amino acid site substitutions compared with the SAl4-14-2 vaccine, key sites that associated with JEV’s antigenic activity and neurovirulence were unchanged. The SA14-14-2 vaccine should therefore be effective in preventing JEV infection in the Huaihua region.

Keywords: Japanese Encephalitis Virus; Mosquitoes; Culex spp.; Pigs; China.


#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.



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.