#Surveillance for #Zika in #Mexico: naturally infected #mosquitoes in #urban and semi-urban areas (Pathog Glob Health, abstract)

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

Pathog Glob Health. 2020 Jan 5:1-6. doi: 10.1080/20477724.2019.1706291. [Epub ahead of print]

Surveillance for Zika in Mexico: naturally infected mosquitoes in urban and semi-urban areas.

Correa-Morales F1, González-Acosta C2, Mejía-Zúñiga D3, Huerta H4, Pérez-Rentería C4, Vazquez-Pichardo M4, Ortega-Morales AI5, Hernández-Triana LM6, Salazar-Bueyes VM1, Moreno-García M7.

Author information: 1 Subdirección del Programa de Enfermedades Transmitidas por Vectores, Centro Nacional de Programas Preventivos y Control de Enfermedades, Ciudad de México, México. 2 Coordinación de Enfermedades Transmitidas por Vector y Zoonosis, Servicios de Salud de Morelos, Cuernavaca, México. 3 Unidad de Investigación Entomológica y Bioensayos-Servicios de Salud de Chihuahua, Chihuahua, México. 4 Laboratorio de Entomología, Instituto de Diagnóstico y Referencia Epidemiológicos ‘Dr. Manuel Martínez Báez’, Ciudad de México, México. 5 Departamento de Parasitología, Universidad Autónoma Agraria Antonio Narro Unidad Laguna, Torreón, México. 6 Animal and Plant Health Agency, Virology Department, Wildlife Zoonoses and Vector-Borne Diseases Research Group, Addlestone, UK. 7 Unidad de Investigación Entomológica y Bioensayos-Centro Regional de Control de Vectores Panchimalco-Servicios de Salud de Morelos, Jojutla, México.

 

Abstract

Zika cases have been reported in 29 out of the 32 states of Mexico. Information regarding which mosquito species might be driving Zika virus transmission/maintenance in nature must be regularly updated. From January 2017 to November 2018, mosquitoes were collected indoors and outdoors using the CDC backpack aspirator in urban and semi-urban areas with evidence of mosquito-borne disease transmission. 3873 mosquito pools were tested for Zika infection using the CDC Trioplex real-time RT-PCR. For each collected specie, maximum likelihood estimator of infection rate (MLE) was estimated. Results showed 492 mosquito pools positive for Zika virus RNA. The majority of the positive pools were Aedes (Stegomyia) aegypti (Linnaeus) (54.6%, MLE = 19) (males and females) and Culex (Culex) quinquefasciatus (Say) (19.5%, MLE = 16.8). For the first time, ZIKV infection was detected in Ae. (Georgecraigius) epactius (Dyar and Knab) (MLE = 17.1), Cx. (Melanoconion) erraticus (Dyar and Knab) (MLE = non-estimable), Culiseta (Culiseta) inornata (Williston) (MLE = non estimable), and Cs (Cs.) particeps (Adams) (MLE = 369.5). Other detected species were: Ae. (Stg.) albopictus (Skuse) (MLE = 90.5), Cx. (Cx.) coronator s.l. (Dyar and Knab) (MLE = 102.8) and Cx. (Cx.) tarsalis (Coquillett) (MLE = 117.2). However, our results do not allow for the incrimination of these species as vectors of ZIKV. Routine surveillance should start to consider other mosquito species across the taxonomic spectrum of the Culicidae.

KEYWORDS: Arbovirus; Culicidae; mosquito-borne diseases; vector control

PMID: 31902313 DOI: 10.1080/20477724.2019.1706291

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

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#Entomological Data and #Detection of #WNV in #Mosquitoes in #Greece (2014–2016), Before Disease Re-Emergence in 2017 (Vector Borne Zoo Dis., abstract)

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

Entomological Data and Detection of West Nile Virus in Mosquitoes in Greece (2014–2016), Before Disease Re-Emergence in 2017

Eleni Patsoula, Stavroula Beleri, Nikolaos Tegos, Rima Mkrtsian, Annita Vakali, and Danai Pervanidou

Published Online: 11 Nov 2019 / DOI: https://doi.org/10.1089/vbz.2018.2422

 

Abstract

West Nile virus (WNV) cases were seasonally recorded in humans and animals in Greece, from 2010 to 2014, and circulation of the virus was detected in different Regional Units of the country. Small scale entomological surveillance activities were carried out by several regions and regional units in Greece, during 2014–2016, with the participation of subcontractors for the vector control programs aiming to record presence/absence of mosquito species, and monitor and control mosquito populations. Mosquito traps were placed in rural and urban sites; specimens were collected, morphologically characterized, and pooled by date of collection, location, and species types. Mosquito pools containing Culex pipiens, Aedes caspius, and Aedes albopictus were examined for the presence of WNV and positive pools were detected in different areas of the country. Sequencing of a selected number of amplicons revealed WNV lineage 2 partial NS5 gene sequences. In this study, we present data on the mosquito species composition in the areas of study and WNV detection from several parts of Greece, in 6, 11, and 26 mosquito pools corresponding to the years 2014, 2015, and 2016, respectively. A total of 15 WNV human infections were reported to the public health authorities of the country in 2014, whereas no human cases were detected for 2015–2016. Taking into consideration the complex epidemiological profile of WNV and unforeseen changes in its circulation, re-emergence of WNV human cases in Greece was possible and expected, thus rendering surveillance activities imperative.

Keywords: West Nile Virus; Mosquitoes; Aedes spp.; Culex spp.; Greece.

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#Epidemiologic, #Entomologic, and #Virologic Factors of the 2014–15 #RossRiver Virus #Outbreak, #Queensland, #Australia (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 12—December 2019 / Research

Epidemiologic, Entomologic, and Virologic Factors of the 2014–15 Ross River Virus Outbreak, Queensland, Australia

Cassie C. Jansen, Martin A. Shivas, Fiona J. May, Alyssa T. Pyke, Michael B. Onn, Kerryn Lodo, Sonja Hall-Mendelin, Jamie L. McMahon, Brian L. Montgomery, Jonathan M. Darbro, Stephen L. Doggett, and Andrew F. van den Hurk

Author affiliations: Communicable Diseases Branch, Queensland Government Department of Health, Herston, Queensland, Australia (C.C. Jansen, K. Lodo); Brisbane City Council, Fortitude Valley, Queensland, Australia (M.A. Shivas, M.B. Onn); Metro North Hospital and Health Service, Windsor, Queensland, Australia (F.J. May); Forensic and Scientific Services, Queensland Government Department of Health, Coopers Plains, Queensland, Australia (A.T. Pyke, S. Hall-Mendelin, J.L. McMahon, A.F. van den Hurk); Metro South Hospital and Health Service, Coopers Plains (B.L. Montgomery); Queensland Institute of Medical Research Berghofer, Herston (J.M. Darbro); University of Sydney and Westmead Hospital, Sydney, New South Wales, Australia (S.L. Doggett)

 

Abstract

Australia experienced its largest recorded outbreak of Ross River virus (RRV) during the 2014–15 reporting year, comprising >10,000 reported cases. We investigated epidemiologic, entomologic, and virologic factors that potentially contributed to the scale of the outbreak in Queensland, the state with the highest number of notifications (6,371). Spatial analysis of human cases showed that notifications were geographically widespread. In Brisbane, human case notifications and virus detections in mosquitoes occurred across inland and coastal locations. Viral sequence data demonstrated 2 RRV lineages (northeastern genotypes I and II) were circulating, and a new strain containing 3 unique amino acid changes in the envelope 2 protein was identified. Longitudinal mosquito collections demonstrated unusually high relative abundance of Culex annulirostris and Aedes procax mosquitoes, attributable to extensive freshwater larval habitats caused by early and persistent rainfall during the reporting year. Increased prevalence of these mosquitoes probably contributed to the scale of this outbreak.

Keywords: Ross River Virus; Mosquitoes; Culex spp.; Aedes spp.; Queensland; Australia.

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RNAi-based #bioinsecticide for #Aedes #mosquito #control (Sci Rep., abstract)

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

Sci Rep. 2019 Mar 11;9(1):4038. doi: 10.1038/s41598-019-39666-5.

RNAi-based bioinsecticide for Aedes mosquito control.

Lopez SBG1, Guimarães-Ribeiro V1, Rodriguez JVG1, Dorand FAPS1, Salles TS1, Sá-Guimarães TE1, Alvarenga ESL1, Melo ACA1,2, Almeida RV1, Moreira MF3,4.

Author information: 1 Universidade Federal do Rio de Janeiro, Departamento de Bioquímica, Instituto de Química, 21941-909, Rio de Janeiro, RJ, Brazil. 2 Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, RJ, Brazil. 3 Universidade Federal do Rio de Janeiro, Departamento de Bioquímica, Instituto de Química, 21941-909, Rio de Janeiro, RJ, Brazil. monica@iq.ufrj.br. 4 Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, RJ, Brazil. monica@iq.ufrj.br.

 

Abstract

Zika virus infection and dengue and chikungunya fevers are emerging viral diseases that have become public health threats. Their aetiologic agents are transmitted by the bite of genus Aedes mosquitoes. Without effective therapies or vaccines, vector control is the main strategy for preventing the spread of these diseases. Increased insecticide resistance calls for biorational actions focused on control of the target vector population. The chitin required for larval survival structures is a good target for biorational control. Chitin synthases A and B (CHS) are enzymes in the chitin synthesis pathway. Double-stranded RNA (dsRNA)-mediated gene silencing (RNAi) achieves specific knockdown of target proteins. Our goal in this work, a new proposed RNAi-based bioinsecticide, was developed as a potential strategy for mosquito population control. DsRNA molecules that target five different regions in the CHSA and B transcript sequences were produced in vitro and in vivo through expression in E. coli HT115 and tested by direct addition to larval breeding water. Mature and immature larvae treated with dsRNA targeting CHS catalytic sites showed significantly decreased viability associated with a reduction in CHS transcript levels. The few larval and adult survivors displayed an altered morphology and chitin content. In association with diflubenzuron, this bioinsecticide exhibited insecticidal adjuvant properties.

PMID: 30858430 DOI: 10.1038/s41598-019-39666-5

Keywords: Arbovirus; Mosquitoes; Aedes spp.; Insecticides.

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A #Gut #Commensal Bacterium Promotes #Mosquito Permissiveness to #Arboviruses (Cell Host Microbe, abstract)

[Source: Cell Host & Microbe, full page: (LINK). Abstract, edited.]

A Gut Commensal Bacterium Promotes Mosquito Permissiveness to Arboviruses

Pa Wu, Peng Sun, Kaixiao Nie, Yibin Zhu, Mingyu Shi, Changguang Xiao, Han Liu, Qiyong Liu, Tongyan Zhao, Xiaoguang Chen, Hongning Zhou, Penghua Wang, Gong Cheng 9

Published: December 27, 2018 / DOI:https://doi.org/10.1016/j.chom.2018.11.004

 

Highlights

  • The gut commensal Serratia marcescens promotes mosquito permissiveness to arboviruses
  • S. marcescens facilitates arboviral infection via a secreted protein named SmEnhancin
  • SmEnhancin digests gut membrane-bound mucins to enhance viral dissemination in mosquitoes
  • S. marcescens enhances the susceptibility of field mosquitoes to dengue virus

 

Summary

Mosquitoes are hematophagous vectors that can acquire human viruses in their intestinal tract. Here, we define a mosquito gut commensal bacterium that promotes permissiveness to arboviruses. Antibiotic depletion of gut bacteria impaired arboviral infection of a lab-adapted Aedes aegypti mosquito strain. Reconstitution of individual cultivable gut bacteria in antibiotic-treated mosquitoes identified Serratia marcescens as a commensal bacterium critical for efficient arboviral acquisition.S. marcescens facilitates arboviral infection through a secreted protein named SmEnhancin, which digests membrane-bound mucins on the mosquito gut epithelia, thereby enhancing viral dissemination. Field Aedes mosquitoes positive forS. marcescens were more permissive to dengue virus infection than those free of S. marcescens. Oral introduction ofS. marcescens into field mosquitoes that lack this bacterium rendered these mosquitoes highly susceptible to arboviruses. This study defines a commensal-driven mechanism that contributes to vector competence, and extends our understanding of multipartite interactions among hosts, the gut microbiome, and viruses.

Keywords: mosquito – microbiota  – arbovirus – Serratia marcescens – Enhancin

Keywords: Arbovirus; Mosquitoes; Aedes spp.; Serratia marcescens.

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#Construction sites in #Miami-Dade County, #Florida are highly favorable #environments for vector #mosquitoes (PLoS One, abstract)

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

PLoS One. 2018 Dec 20;13(12):e0209625. doi: 10.1371/journal.pone.0209625. eCollection 2018.

Construction sites in Miami-Dade County, Florida are highly favorable environments for vector mosquitoes.

Wilke ABB1, Vasquez C2, Petrie W2, Caban-Martinez AJ1, Beier JC1.

Author information: 1 Department of Public Health Sciences, Miller School of Medicine, University of Miami, Miami, FL, United States of America. 2 Miami-Dade County Mosquito Control Division, Miami, FL, United States of America.

 

Abstract

Urbanization is increasing globally, and construction sites are an integral part of the urbanization process. It is unknown to what extent construction sites create favorable breeding conditions for mosquitoes. The main objectives of the present study were to identify what species of mosquitoes are present at construction sites and the respective physical features associated with their production. Eleven construction sites were cross-sectionally surveyed for the presence of mosquitoes in Miami-Dade County, Florida including in areas previously affected by the Zika virus outbreak in 2016. A total of 3.351 mosquitoes were collected; 2.680 adults and 671 immatures. Aedes aegypti and Culex quinquefasciatus comprised 95% of all collected mosquitoes and were the only species found in their immature forms breeding inside construction sites. Results for the Shannon and Simpson indices, considering both immature and adult specimens, yielded the highest values for Cx. quinquefasciatus and Ae. aegypti. The individual rarefaction curves indicated that sampling sufficiency was highly asymptotic for Cx. quinquefasciatus and Ae. aegypti, and the plots of cumulative species abundance (ln S), Shannon index (H) and log evenness (ln E) (SHE) revealed the lack of heterogeneity of species composition, diversity and evenness for the mosquitoes found breeding in construction sites. The most productive construction site breeding features were elevator shafts, Jersey plastic barriers, flooded floors and stair shafts. The findings of this study indicate that vector mosquitoes breed in high numbers at construction sites and display reduced biodiversity comprising almost exclusively Ae. aegypti and Cx. quinquefasciatus. Such findings suggest that early phase construction sites have suitable conditions for the proliferation of vector mosquitoes. More studies are needed to identify modifiable worker- and organizational-level factors to improve mosquito control practices and guide future mosquito control strategies in urban environments.

PMID: 30571764 DOI: 10.1371/journal.pone.0209625

Keywords: Mosquitoes; Aedes spp.; Culex spp.; Aedes aegypti; Culex quinquefasciatus; USA; Florida.

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#Sequential #Infection of #Aedes aegypti #Mosquitoes with #Chikungunya Virus and #Zika Virus Enhances Early Zika Virus Transmission (Insects, abstract)

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

Insects. 2018 Dec 1;9(4). pii: E177. doi: 10.3390/insects9040177.

Sequential Infection of Aedes aegypti Mosquitoes with Chikungunya Virus and Zika Virus Enhances Early Zika Virus Transmission.

Magalhaes T1, Robison A2, Young MC3, Black WC 4th4, Foy BD5, Ebel GD6, Rückert C7.

Author information: 1 Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523, USA. Tereza.Magalhaes@colostate.edu. 2 Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523, USA. lexir5394@gmail.com. 3 Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523, USA. emceeyoung@gmail.com. 4 Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523, USA. William.Black@colostate.edu. 5 Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523, USA. Brian.Foy@colostate.edu. 6 Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523, USA. Gregory.Ebel@colostate.edu. 7 Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523, USA. Claudia.Rueckert@Colostate.edu.

 

Abstract

In urban settings, chikungunya, Zika, and dengue viruses are transmitted by Aedes aegypti mosquitoes. Since these viruses co-circulate in several regions, coinfection in humans and vectors may occur, and human coinfections have been frequently reported. Yet, little is known about the molecular aspects of virus interactions within hosts and how they contribute to arbovirus transmission dynamics. We have previously shown that Aedes aegypti exposed to chikungunya and Zika viruses in the same blood meal can become coinfected and transmit both viruses simultaneously. However, mosquitoes may also become coinfected by multiple, sequential feeds on single infected hosts. Therefore, we tested whether sequential infection with chikungunya and Zika viruses impacts mosquito vector competence. We exposed Ae. aegypti mosquitoes first to one virus and 7 days later to the other virus and compared infection, dissemination, and transmission rates between sequentially and single infected groups. We found that coinfection rates were high after sequential exposure and that mosquitoes were able to co-transmit both viruses. Surprisingly, chikungunya virus coinfection enhanced Zika virus transmission 7 days after the second blood meal. Our data demonstrate heterologous arbovirus synergism within mosquitoes, by unknown mechanisms, leading to enhancement of transmission under certain conditions.

KEYWORDS: Zika; arboviruses; chikungunya; coinfection; mosquitoes; sequential infection

PMID: 30513725 DOI: 10.3390/insects9040177

Keywords: Arbovirus; Chikungunya fever; Zika Virus; Dengue fever; Mosquitoes; Aedes spp.; Aedes aegypti.

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