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Lu L, Zhang F, Oude Munnink BB, Munger E, Sikkema RS, Pappa S, Tsioka K, Sinigaglia A, Dal Molin E, Shih BB, Günther A, Pohlmann A, Ziegler U, Beer M, Taylor RA, Bartumeus F, Woolhouse M, Aarestrup FM, Barzon L, Papa A, Lycett S, Koopmans MPG. West Nile virus spread in Europe: Phylogeographic pattern analysis and key drivers. PLoS Pathog 2024; 20:e1011880. [PMID: 38271294 PMCID: PMC10810478 DOI: 10.1371/journal.ppat.1011880] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 12/04/2023] [Indexed: 01/27/2024] Open
Abstract
BACKGROUND West Nile virus (WNV) outbreaks in birds, humans, and livestock have occurred in multiple areas in Europe and have had a significant impact on animal and human health. The patterns of emergence and spread of WNV in Europe are very different from those in the US and understanding these are important for guiding preparedness activities. METHODS We mapped the evolution and spread history of WNV in Europe by incorporating viral genome sequences and epidemiological data into phylodynamic models. Spatially explicit phylogeographic models were developed to explore the possible contribution of different drivers to viral dispersal direction and velocity. A "skygrid-GLM" approach was used to identify how changes in environments would predict viral genetic diversity variations over time. FINDINGS Among the six lineages found in Europe, WNV-2a (a sub-lineage of WNV-2) has been predominant (accounting for 73% of all sequences obtained in Europe that have been shared in the public domain) and has spread to at least 14 countries. In the past two decades, WNV-2a has evolved into two major co-circulating clusters, both originating from Central Europe, but with distinct dynamic history and transmission patterns. WNV-2a spreads at a high dispersal velocity (88km/yr-215 km/yr) which is correlated to bird movements. Notably, amongst multiple drivers that could affect the spread of WNV, factors related to land use were found to strongly influence the spread of WNV. Specifically, the intensity of agricultural activities (defined by factors related to crops and livestock production, such as coverage of cropland, pasture, cultivated and managed vegetation, livestock density) were positively associated with both spread direction and velocity. In addition, WNV spread direction was associated with high coverage of wetlands and migratory bird flyways. CONCLUSION Our results suggest that-in addition to ecological conditions favouring bird- and mosquito- presence-agricultural land use may be a significant driver of WNV emergence and spread. Our study also identified significant gaps in data and the need to strengthen virological surveillance in countries of Central Europe from where WNV outbreaks are likely seeded. Enhanced monitoring for early detection of further dispersal could be targeted to areas with high agricultural activities and habitats of migratory birds.
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Affiliation(s)
- Lu Lu
- Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
- Usher Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Feifei Zhang
- Usher Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Bas B. Oude Munnink
- Erasmus MC, Viroscience and Pandemic and Disaster Preparedness Centre, Rotterdam, the Netherlands
| | - Emmanuelle Munger
- Erasmus MC, Viroscience and Pandemic and Disaster Preparedness Centre, Rotterdam, the Netherlands
| | - Reina S. Sikkema
- Erasmus MC, Viroscience and Pandemic and Disaster Preparedness Centre, Rotterdam, the Netherlands
| | - Styliani Pappa
- Department of Microbiology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Katerina Tsioka
- Department of Microbiology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | | | | | - Barbara B. Shih
- Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Anne Günther
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald-Riems, Germany
| | - Anne Pohlmann
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald-Riems, Germany
| | - Ute Ziegler
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald-Riems, Germany
| | - Martin Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald-Riems, Germany
| | - Rachel A. Taylor
- Department of Epidemiological Sciences, Animal and Plant Health Agency, United Kingdom
| | - Frederic Bartumeus
- Centre for Advanced Studies of Blanes (CEAB-CSIC), Girona, Spain
- Centre for Research on Ecology and Forestry Applications (CREAF), Barcelona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Mark Woolhouse
- Usher Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Frank M. Aarestrup
- Research Group for Genomic Epidemiology, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Luisa Barzon
- Department of Molecular Medicine, University of Padova, Padua, Italy
| | - Anna Papa
- Department of Microbiology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Samantha Lycett
- Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Marion P. G. Koopmans
- Erasmus MC, Viroscience and Pandemic and Disaster Preparedness Centre, Rotterdam, the Netherlands
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Bektore B, Dogan B, Ozkul A, Gozalan A. West Nile virus seropositivity in Alanya, a coastal city in the Mediterranean region of Turkey. Ann Saudi Med 2024; 44:48-54. [PMID: 38311862 PMCID: PMC10839453 DOI: 10.5144/0256-4947.2024.48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 11/03/2023] [Indexed: 02/06/2024] Open
Abstract
BACKGROUND West Nile virus (WNV)-related illness is a global health problem. Understanding the seropositivity rates and identifying the risk factors related to WNV in various animal species including humans is crucial for the implementation of effective prevention strategies. OBJECTIVES Assess the rate of seropositivity and the risk factors associated with WNV seropositivity. DESIGN Descriptive, cross-sectional. SETTING Microbiology and virology departments in a veterinary college. PATIENTS AND METHODS In a sample of healthy human participants in Alanya, located close to regions where WNV activity has been detected, anti-WNV IgG antibody detection was performed using enzyme-linked immunosorbent assays. The positive results were confirmed by virus neutralization tests (VNTs). The sample was compared with a second group of age- and gender-matched healthy subjects selected from a previous cross-sectional study. MAIN OUTCOME MEASURES Determination of the seropositivity and risk factors that were associated with WNV in healthy humans. SAMPLE SIZE 87 in current study; 356 in previous study. RESULTS The first group of 87, which had a high risk of encountering vector mosquitoes, had a positivity rate of 8% (7/87), whereas positivity in the second group was 4.5% (16/356; P=.181). In the entire sample, the anti-WNV IgG antibody was positive in 23 out of 443 (5.2%) samples by the ELISA test. Among these 23 samples, ten were confirmed as positive using VNTs. Therefore, the WNV IgG seropositivity was 2.3% (10/442). Confirmed IgG seropositivity rates were higher among male (3.8%) than female participants (0.9%; P=.054) and among adults aged ≥45 years (4%) than those aged 18-44 years (0.8%; P=.048). CONCLUSION This study highlights the presence of WNV infection in the research region. More comprehensive and multidisciplinary studies are required to increase our knowledge about this zoonotic infection including risk factors in line with the One Health approach. LIMITATIONS Small sample size.
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Affiliation(s)
- Bayhan Bektore
- From the Department of Medical Microbiology, Ministry of Health Alanya Alaadin Keykubat University, Alanya Education and Research Hospital, Antalya, Alanya, Turkey
| | - Bora Dogan
- From the Department of Medical Microbiology, Urla State Hospital, Izmir, Turkey
| | - Akyut Ozkul
- From the Department of Virology, Faculty of Veterinary Medicine, Ankara University, Ankara, Turkey
| | - Aysegul Gozalan
- From the Department of Medical Microbiology, Ministry of Health Alanya Alaadin Keykubat University, Alanya Education and Research Hospital, Antalya, Alanya, Turkey
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Erdogan Bamac O, Cizmecigil UY, Mete A, Yilmaz A, Aydin O, Tali HE, Tali BH, Yilmaz SG, Gurel A, Turan N, Ozsoy S, Vatansever Celik E, Sadeyen JR, Roman-Sosa G, Iqbal M, Richt JA, Yilmaz H. Emergence of West Nile Virus Lineage-2 in Resident Corvids in Istanbul, Turkey. Vector Borne Zoonotic Dis 2021; 21:892-899. [PMID: 34748405 DOI: 10.1089/vbz.2021.0010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
West Nile fever is a vector-borne viral disease affecting animals and humans causing significant health and economic problems globally. This study was aimed at investigating circulating West Nile virus (WNV) strains in free-ranging corvids in Istanbul, Turkey. Brain, liver, and kidney were collected from corvids (n = 34) between June 2019 and April 2020 and analyzed for the presence of WNV-specific RNA by quantitative RT-PCR. In addition, histopathologic and immunohistochemical examinations were also performed. Samples found to be positive by qRT-PCR were partially sequenced. WNV-specific RNA was detected in 8 of 34 corvids analyzed, which included 7 hooded crows (Corvus cornix) and 1 Eurasian magpie (Pica pica). Phylogenetic analysis based on partial WNV sequences from the 8 WNV-positive corvids identified in this study revealed that all sequences clustered within the WNV lineage-2; they were at least 97% homologues to WNV lineage-2 sequences from Slovakia, Italy, Czechia, Hungary, Senegal, Austria, Serbia, Greece, Bulgaria, and Germany. WNV sequences showed a divergence (87.94-94.46%) from sequences reported from Romania, Central African Republic, South Africa, Madagascar, Israel, and Cyprus, which clustered into a different clade of WNV lineage-2. Common histopathologic findings of WNV-positive corvids included lymphoplasmacytic hepatitis, myocarditis, and splenitis. The liver and heart were found to be the tissues most consistently positive for WNV-specific antigen by immunohistochemistry, followed by the kidney and brain. This study demonstrates for the first time the existence of WNV virus belonging to the genetic lineage-2 in resident corvids in Istanbul, Turkey. We hypothesize that the WNV strains circulating in Istanbul are possibly the result of a spillover event from Europe. Since WNV is a zoonotic pathogen transmitted by mosquito vectors, the emergence of WNV in Istanbul also poses a risk to humans and other susceptible animals in this densely populated city and needs to be addressed by animal and public health authorities.
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Affiliation(s)
- Ozge Erdogan Bamac
- Department of Pathology, and Veterinary Faculty, Istanbul University-Cerrahpasa, Avcilar, Istanbul, Turkey
| | - Utku Y Cizmecigil
- Department of Virology, Veterinary Faculty, Istanbul University-Cerrahpasa, Avcilar, Istanbul, Turkey
| | - Asli Mete
- California Animal Health and Food Safety Laboratory, Davis Branch, University of California-Davis, Davis, California, USA
| | - Aysun Yilmaz
- Department of Virology, Veterinary Faculty, Istanbul University-Cerrahpasa, Avcilar, Istanbul, Turkey
| | - Ozge Aydin
- Department of Virology, Veterinary Faculty, Istanbul University-Cerrahpasa, Avcilar, Istanbul, Turkey
| | - Hasan E Tali
- Department of Virology, Veterinary Faculty, Istanbul University-Cerrahpasa, Avcilar, Istanbul, Turkey
| | - Besim H Tali
- Department of Virology, Veterinary Faculty, Istanbul University-Cerrahpasa, Avcilar, Istanbul, Turkey
| | - Semaha G Yilmaz
- Department of Virology, Veterinary Faculty, Istanbul University-Cerrahpasa, Avcilar, Istanbul, Turkey
| | - Aydin Gurel
- Department of Pathology, and Veterinary Faculty, Istanbul University-Cerrahpasa, Avcilar, Istanbul, Turkey
| | - Nuri Turan
- Department of Virology, Veterinary Faculty, Istanbul University-Cerrahpasa, Avcilar, Istanbul, Turkey
| | - Serhat Ozsoy
- Department of Wild Animals and Ecology, Veterinary Faculty, Istanbul University-Cerrahpasa, Avcilar, Istanbul, Turkey
| | - Ezgi Vatansever Celik
- Department of Wild Animals and Ecology, Veterinary Faculty, Istanbul University-Cerrahpasa, Avcilar, Istanbul, Turkey
| | - Jean-Remy Sadeyen
- Avian Influenza Group, The Pirbright Institute, Pirbright, Woking, United Kingdom
| | - Gleyder Roman-Sosa
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA
| | - Munir Iqbal
- Avian Influenza Group, The Pirbright Institute, Pirbright, Woking, United Kingdom
| | - Juergen A Richt
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA
| | - Huseyin Yilmaz
- Department of Virology, Veterinary Faculty, Istanbul University-Cerrahpasa, Avcilar, Istanbul, Turkey
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Phylogenetic analysis of West Nile virus: first report of lineage 1 in donkey in Turkey. Trop Anim Health Prod 2021; 53:453. [PMID: 34536145 DOI: 10.1007/s11250-021-02892-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 09/10/2021] [Indexed: 10/20/2022]
Abstract
West Nile virus (WNV), a member of the Flaviviridae, is a major arbovirus that causes West Nile fever. Previous data showed the prevalence of the WNV serologically and molecular in Turkey, and the presence of lineage 1 in horses and humans has been reported. This is the first notification of partial phylogeny of WNV detected in donkeys in the northeast of Turkey (on the Iranian border). Blood serum samples collected from 25 donkeys without clinical symptoms were tested by RT-PCR. Sequence analysis of the sample detected as positive was performed. Multiple sequence alignments of reference sequences taken from GenBank were performed using the ClustalW method using the MEGA6 program. Partial nucleotide sequences of the capsid gene coding region revealed that the strains are closely related to viruses of lineage 1, clade 1a. According to the phylogenetic tree, the TUR/Igdir/donkey strain was included in the same cluster as the strain (KJ958922) previously obtained from horses in Turkey and the strain (GQ851658) from the Central African Republic. This study is the first report to show the circulation of WNV lineage 1 in donkeys in Turkey.
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Autochthonous Transmission of West Nile Virus by a New Vector in Iran, Vector-Host Interaction Modeling and Virulence Gene Determinants. Viruses 2020; 12:v12121449. [PMID: 33339336 PMCID: PMC7766443 DOI: 10.3390/v12121449] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/27/2020] [Accepted: 12/14/2020] [Indexed: 02/07/2023] Open
Abstract
Using molecular techniques and bioinformatics tools, we studied the vector-host interactions and the molecular epidemiology of West Nile virus (WNV) in western Iran. Mosquitoes were collected during 2017 and 2018. DNA typing assays were used to study vector-host interactions. Mosquitoes were screened by RT-PCR for the genomes of five virus families. WNV-positive samples were fully sequenced and evolutionary tree and molecular architecture were constructed by Geneious software and SWISS-MODEL workspace, respectively. A total of 5028 mosquito specimens were collected and identified. The most prevalent species was Culex (Cx.) pipiens complex (57.3%). Analysis of the blood-feeding preferences of blood-fed mosquitoes revealed six mammalian and one bird species as hosts. One mosquito pool containing non-blood-fed Cx. theileri and one blood-fed Culex pipiens pipiens (Cpp.) biotype pipiens were positive for WNV. A phylogram indicated that the obtained WNV sequences belonged to lineage 2, subclade 2 g. Several amino acid substitutions suspected as virulence markers were observed in the Iranian WNV strains. The three-dimensional structural homology model of the E-protein identified hot spot domains known to facilitate virus invasion and neurotropism. The recent detection of WNV lineage 2 in mosquitoes from several regions of Iran in consecutive years suggests that the virus is established in the country.
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Ergünay K, Polat C, Özkul A. Vector-borne viruses in Turkey: A systematic review and bibliography. Antiviral Res 2020; 183:104934. [PMID: 32949637 DOI: 10.1016/j.antiviral.2020.104934] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 09/09/2020] [Accepted: 09/11/2020] [Indexed: 11/25/2022]
Abstract
Turkey serves as a natural hub for the dissemination of vector-borne viruses and provides many suitable habitats with diverse ecologies for introduction and establishment of new pathogens. This manuscript provides an updated systematic review and meta-analysis of the vector-borne viruses documented in Turkey. Following web-based identification, screening and eligibility evaluation, 291 published reports were reviewed. The publications were categorized and listed as a supplementary bibliography accompanying the manuscript. In brief, Crimean-Congo hemorrhagic fever virus (CCHFV) and West Nile virus (WNV) are currently documented as prominent tick and mosquito-borne viral pathogens in Turkey. CCHFV produces a significant number of infections annually, with severe outcome or death in a portion of cases. WNV gained attention following the clustering of cases in 2010. Exposure and infections with sandfly-borne phleboviruses, such as Toscana virus, are indigenous and widespread. Epidemiology, risk factors, symptomatic infections in susceptible hosts, vectors and reservoirs for these pathogens have been explored in detail. Detection of novel viruses in mosquitoes, sandflies and ticks from several regions is of particular interest, despite scarce information on their epidemiology and pathogenicity in vertebrates. Introduction and emergence of viruses transmitted by invasive Aedes mosquitoes constitute a threat, albeit only imported infections have so far been documented. Detection of Rift valley fever virus exposure is also of concern, due to its detrimental effects on livestock and spillover infections in humans. Vigilance to identify and diagnose probable cases as well as vector surveillance for established and potential pathogens is therefore, imperative.
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Affiliation(s)
- Koray Ergünay
- Hacettepe University, Faculty of Medicine, Department of Medical Microbiology, Virology Unit, Ankara, 06100, Turkey.
| | - Ceylan Polat
- Hacettepe University, Faculty of Medicine, Department of Medical Microbiology, Virology Unit, Ankara, 06100, Turkey
| | - Aykut Özkul
- Ankara University, Faculty of Veterinary Medicine, Department of Virology, Ankara, 06110, Turkey
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Akıner MM, Öztürk M, Başer AB, Günay F, Hacıoğlu S, Brinkmann A, Emanet N, Alten B, Özkul A, Nitsche A, Linton YM, Ergünay K. Arboviral screening of invasive Aedes species in northeastern Turkey: West Nile virus circulation and detection of insect-only viruses. PLoS Negl Trop Dis 2019; 13:e0007334. [PMID: 31059502 PMCID: PMC6522068 DOI: 10.1371/journal.pntd.0007334] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 05/16/2019] [Accepted: 03/26/2019] [Indexed: 12/19/2022] Open
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. pipiens mosquitoes. 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.
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Affiliation(s)
- Mustafa M. Akıner
- Recep Tayyip Erdogan University, Faculty of Arts and Sciences, Department of Biology, Rize, TURKEY
| | - Murat Öztürk
- Recep Tayyip Erdogan University, Faculty of Arts and Sciences, Department of Biology, Rize, TURKEY
| | - Aykut Buğra Başer
- Recep Tayyip Erdogan University, Faculty of Arts and Sciences, Department of Biology, Rize, TURKEY
| | - Filiz Günay
- Hacettepe University; Faculty of Sciences, Department of Biology, Division of Ecology, Ankara, TURKEY
| | - Sabri Hacıoğlu
- Ankara University; Faculty of Veterinary Medicine, Department of Virology, Ankara, TURKEY
| | - Annika Brinkmann
- Robert Koch Institute; Center for Biological Threats and Special Pathogens 1 (ZBS-1), Berlin, GERMANY
| | - Nergis Emanet
- Hacettepe University; Faculty of Medicine, Department of Medical Microbiology, Virology Unit, Ankara, TURKEY
| | - Bülent Alten
- Hacettepe University; Faculty of Sciences, Department of Biology, Division of Ecology, Ankara, TURKEY
| | - Aykut Özkul
- Ankara University; Faculty of Veterinary Medicine, Department of Virology, Ankara, TURKEY
| | - Andreas Nitsche
- Robert Koch Institute; Center for Biological Threats and Special Pathogens 1 (ZBS-1), Berlin, GERMANY
| | - Yvonne-Marie Linton
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, United States of America
- Walter Reed Biosystematics Unit, Smithsonian Institution Museum Support Center, Suitland, United States of America
| | - Koray Ergünay
- Hacettepe University; Faculty of Medicine, Department of Medical Microbiology, Virology Unit, Ankara, TURKEY
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Vilibic-Cavlek T, Savic V, Petrovic T, Toplak I, Barbic L, Petric D, Tabain I, Hrnjakovic-Cvjetkovic I, Bogdanic M, Klobucar A, Mrzljak A, Stevanovic V, Dinjar-Kujundzic P, Radmanic L, Monaco F, Listes E, Savini G. Emerging Trends in the Epidemiology of West Nile and Usutu Virus Infections in Southern Europe. Front Vet Sci 2019; 6:437. [PMID: 31867347 PMCID: PMC6908483 DOI: 10.3389/fvets.2019.00437] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 11/19/2019] [Indexed: 02/05/2023] Open
Abstract
The epidemiology of West Nile (WNV) and Usutu virus (USUV) has changed dramatically over the past two decades. Since 1999, there have been regular reports of WNV outbreaks and the virus has expanded its area of circulation in many Southern European countries. After emerging in Italy in 1996, USUV has spread to other countries causing mortality in several bird species. In 2009, USUV seroconversion in horses was reported in Italy. Co-circulation of both viruses was detected in humans, horses and birds. The main vector of WNV and USUV in Europe is Culex pipiens, however, both viruses were found in native Culex mosquito species (Cx. modestus, Cx. perexiguus). Experimental competence to transmit the WNV was also proven for native and invasive mosquitoes of Aedes and Culex genera (Ae. albopictus, Ae. detritus, Cx. torrentium). Recently, Ae. albopictus and Ae. japonicus naturally-infected with USUV were reported. While neuroinvasive human WNV infections are well-documented, USUV infections are sporadically detected. However, there is increasing evidence of a role of USUV in human disease. Seroepidemiological studies showed that USUV circulation is more common than WNV in some endemic regions. Recent data showed that WNV strains detected in humans, horses, birds, and mosquitoes mainly belong to lineage 2. In addition to European USUV lineages, some reports indicate the presence of African USUV lineages as well. The trends in WNV/USUV range and vector expansion are likely to continue in future years. This mini-review provides an update on the epidemiology of WNV and USUV infections in Southern Europe within a multidisciplinary "One Health" context.
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Affiliation(s)
- Tatjana Vilibic-Cavlek
- Department of Virology, Croatian Institute of Public Health, Zagreb, Croatia
- School of Medicine, University of Zagreb, Zagreb, Croatia
- *Correspondence: Tatjana Vilibic-Cavlek
| | - Vladimir Savic
- Poultry Center, Croatian Veterinary Institute, Zagreb, Croatia
| | - Tamas Petrovic
- Department for Virology, Scientific Veterinary Institute, Novi Sad, Serbia
| | - Ivan Toplak
- Veterinary Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Ljubo Barbic
- Department of Microbiology and Infectious Diseases With Clinic, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
| | - Dusan Petric
- Laboratory for Medical and Veterinary Entomology, Faculty of Agriculture, University of Novi Sad, Novi Sad, Serbia
| | - Irena Tabain
- Department of Virology, Croatian Institute of Public Health, Zagreb, Croatia
| | - Ivana Hrnjakovic-Cvjetkovic
- Center for Microbiology, Institute of Public Health Vojvodina, Novi Sad, Serbia
- Medical Faculty, University of Novi Sad, Novi Sad, Serbia
| | - Maja Bogdanic
- Department of Virology, Croatian Institute of Public Health, Zagreb, Croatia
| | - Ana Klobucar
- Division of Disinfection, Disinfestation and Pest Control, Andrija Stampar Teaching Institute of Public Health, Zagreb, Croatia
| | - Anna Mrzljak
- School of Medicine, University of Zagreb, Zagreb, Croatia
- Department of Medicine, Merkur University Hospital, Zagreb, Croatia
| | - Vladimir Stevanovic
- Department of Microbiology and Infectious Diseases With Clinic, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
| | | | - Luka Radmanic
- Department of Microbiology and Infectious Diseases With Clinic, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
| | - Federica Monaco
- OIE Reference Center for West Nile Disease, Istituto Zooprofilattico Sperimentale “G. Caporale”, Teramo, Italy
| | - Eddy Listes
- Laboratory for Diagnostics, Croatian Veterinary Institute, Regional Institute Split, Split, Croatia
| | - Giovanni Savini
- OIE Reference Center for West Nile Disease, Istituto Zooprofilattico Sperimentale “G. Caporale”, Teramo, Italy
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Lustig Y, Sofer D, Bucris ED, Mendelson E. Surveillance and Diagnosis of West Nile Virus in the Face of Flavivirus Cross-Reactivity. Front Microbiol 2018; 9:2421. [PMID: 30369916 PMCID: PMC6194321 DOI: 10.3389/fmicb.2018.02421] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 09/21/2018] [Indexed: 01/20/2023] Open
Abstract
West Nile Virus (WNV) is an arthropod-borne flavivirus whose zoonotic cycle includes both mosquitoes and birds as amplifiers and humans and horses as dead-end hosts. In recent years WNV has been spreading globally and is currently endemic in Africa, The Middle East, India, Australia, central and southern Europe, and the Americas. Integrated surveillance schemes and environmental data aim to detect viral circulation and reduce the risk of infection for the human population emphasizing the critical role for One Health principles in public health. Approximately 20% of WNV infected patients develop West Nile Fever while in less than 1%, infection results in West Nile Neurological Disease. Currently, the diagnosis of WNV infection is primarily based on serology, since molecular identification of WNV RNA is unreliable due to the short viremia. The recent emergence of Zika virus epidemic in America and Asia has added another layer of complexity to WNV diagnosis due to significant cross-reactivity between several members of the Flaviviridae family such as Zika, dengue, Usutu, and West Nile viruses. Diagnosis is especially challenging in persons living in regions with flavivirus co-circulation as well as in travelers from WNV endemic countries traveling to Zika or dengue infected areas or vise-versa. Here, we review the recent studies implementing WNV surveillance of mosquitoes and birds within the One Health initiative. Furthermore, we discuss the utility of novel molecular methods, alongside traditional molecular and serological methods, in WNV diagnosis and epidemiological research.
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Affiliation(s)
- Yaniv Lustig
- Central Virology Laboratory, Ministry of Health, Sheba Medical Center, Ramat Gan, Israel
| | - Danit Sofer
- Central Virology Laboratory, Ministry of Health, Sheba Medical Center, Ramat Gan, Israel
| | - Efrat Dahan Bucris
- Central Virology Laboratory, Ministry of Health, Sheba Medical Center, Ramat Gan, Israel
| | - Ella Mendelson
- Central Virology Laboratory, Ministry of Health, Sheba Medical Center, Ramat Gan, Israel.,School of Public Health, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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10
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Abstract
Eastern Europe (EE) has been severely affected by mosquito-borne viruses (moboviruses). In this review, we summarize the epidemiology of moboviruses, with particular attention to West Nile virus (WNV). The study of WNV human cases in EE between 2010 and 2016, revealed that the epidemiology of WNV in EE is complex with the combination of introduction of different WNV strains from lineages 1 and 2, and the establishment of endemic cycles. We found a positive correlation between the risk of WNV re-emergence in an area and the number of human cases reported in the previous year. We also report the main ecological and biological characteristics of the key mosquito species vectors of moboviruses. Recent expansion of invasive mosquito species in EE, mainly Aedes albopictus but also Aedes aegypti and Culex quinquefasciatus, may result in new scenarios with an increased risk of transmission of moboviruses. Main gaps of knowledge in relation to moboviruses and their vectors in EE are identified. Understanding the epidemiology of moboviruses in EE is essential for the improvement of their surveillance and the control of the diseases they cause.
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Affiliation(s)
- Sebastián Napp
- IRTA,Campus de la Universitat Autònoma de Barcelona,Bellaterra, Spain
| | - Dusan Petrić
- University of Novi Sad, Faculty of Agriculture, Laboratory for Medical Entomology, Novi Sad, Serbia
| | - Núria Busquets
- IRTA,Campus de la Universitat Autònoma de Barcelona,Bellaterra, Spain
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11
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Papa A, Zelená H, Papadopoulou E, Mrázek J. Uukuniemi virus, Czech Republic. Ticks Tick Borne Dis 2018; 9:1129-1132. [PMID: 29699908 DOI: 10.1016/j.ttbdis.2018.04.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 04/13/2018] [Accepted: 04/16/2018] [Indexed: 10/17/2022]
Abstract
Following the identification of severe fever with thrombocytopenia syndrome and Heartland viruses, the interest on tick-borne phleboviruses has increased rapidly. Uukuniemi virus has been proposed as a model for tick-borne phleboviruses. However, the number of available sequences is limited. In the current study we performed whole-genome sequencing on two Uukuniemi viral strains isolated in 2000 and 2004 from Ixodes ricinus ticks in the Czech Republic. Both strains cluster together with Potepli63 strain isolated in the country in 1963. Although the Czech strains were isolated many years apart, a high identity was seen at the nucleotide and amino acid levels, suggesting that UUKV has a relatively stable genome.
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Affiliation(s)
- Anna Papa
- Department of Microbiology, Medical School, Aristotle University of Thessaloniki, Greece.
| | - Hana Zelená
- Department of Virology, Institute of Public Health, Ostrava, Czech Republic; University of Defence, Faculty of Military Health Sciences, Hradec Králové, Czech Republic
| | - Elpida Papadopoulou
- Department of Microbiology, Medical School, Aristotle University of Thessaloniki, Greece
| | - Jakub Mrázek
- Department of Molecular Biology, Institute of Public Health, Ostrava, Czech Republic
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12
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Altinli M, Gunay F, Alten B, Weill M, Sicard M. Wolbachia diversity and cytoplasmic incompatibility patterns in Culex pipiens populations in Turkey. Parasit Vectors 2018; 11:198. [PMID: 29558974 PMCID: PMC5859491 DOI: 10.1186/s13071-018-2777-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 03/06/2018] [Indexed: 12/04/2022] Open
Abstract
Background Wolbachia are maternally transmitted bacteria that can manipulate their hosts’ reproduction causing cytoplasmic incompatibility (CI). CI is a sperm-egg incompatibility resulting in embryonic death. Due to this sterilising effect on mosquitoes, Wolbachia are considered for vector control strategies. Important vectors for arboviruses, filarial nematodes and avian malaria, mosquitoes of Culex pipiens complex are suitable for Wolbachia-based vector control. They are infected with Wolbachia wPip strains belonging to five genetically distinct groups (wPip-I to V) within the Wolbachia B supergroup. CI properties of wPip strongly correlate with this genetic diversity: mosquitoes infected with wPip strains from a different wPip group are more likely to be incompatible with each other. Turkey is a critical spot for vector-borne diseases due to its unique geographical position as a natural bridge between Asia, Europe and Africa. However, general wPip diversity, distribution and CI patterns in natural Cx. pipiens (s.l.) populations in the region are unknown. In this study, we first identified wPip diversity in Turkish Cx. pipiens (s.l.) populations, by assigning them to one of the five groups within wPip (wPip-Ito V). We further investigated CI properties between different wPip strains from this region. Results We showed a wPip fixation in Cx. pipiens (s.l.) populations in Turkey by analysing 753 samples from 59 sampling sites. Three wPip groups were detected in the region: wPip-I, wPip-II and wPip-IV. The most dominant group was wPip-II. While wPip-IV was restricted to only two locations, wPip-I and wPip-II had wider distributions. Individuals infected with wPip-II were found co-existing with individuals infected with wPip-I or wPip-IV in some sampling sites. Two mosquito isofemale lines harbouring either a wPip-I or a wPip-II strain were established from a population in northwestern Turkey. Reciprocal crosses between these lines showed that they were fully compatible with each other but bidirectionally incompatible with wPip-IV Istanbul infected line. Conclusion Our findings reveal a high diversity of wPip and CI properties in Cx. pipiens (s.l.) populations in Turkey. Knowledge on naturally occurring CI patterns caused by wPip diversity in Turkey might be useful for Cx. pipiens (s.l.) control in the region.
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Affiliation(s)
- Mine Altinli
- Institut des Sciences de l'Evolution de Montpellier (CNRS-Université de Montpellier-IRD-EPHE), Montpellier, France.
| | - Filiz Gunay
- Faculty of Sciences, Department of Biology, Division of Ecology, VERG Laboratories, Hacettepe University, Ankara, Turkey
| | - Bulent Alten
- Faculty of Sciences, Department of Biology, Division of Ecology, VERG Laboratories, Hacettepe University, Ankara, Turkey
| | - Mylene Weill
- Institut des Sciences de l'Evolution de Montpellier (CNRS-Université de Montpellier-IRD-EPHE), Montpellier, France
| | - Mathieu Sicard
- Institut des Sciences de l'Evolution de Montpellier (CNRS-Université de Montpellier-IRD-EPHE), Montpellier, France.
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13
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Öncü C, Brinkmann A, Günay F, Kar S, Öter K, Sarıkaya Y, Nitsche A, Linton YM, Alten B, Ergünay K. West Nile virus, Anopheles flavivirus, a novel flavivirus as well as Merida-like rhabdovirus Turkey in field-collected mosquitoes from Thrace and Anatolia. INFECTION GENETICS AND EVOLUTION 2017; 57:36-45. [PMID: 29128516 DOI: 10.1016/j.meegid.2017.11.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 11/04/2017] [Accepted: 11/06/2017] [Indexed: 11/30/2022]
Abstract
Mosquitoes are involved in the transmission and maintenance of several viral diseases with significant health impact. Biosurveillance efforts have also revealed insect-specific viruses, observed to cocirculate with pathogenic strains. This report describes the findings of flavivirus and rhabdovirus screening, performed in eastern Thrace and Aegean region of Anatolia during 2016, including and expanding on locations with previously-documented virus activity. A mosquito cohort of 1545 individuals comprising 14 species were collected and screened in 108 pools via generic and specific amplification and direct metagenomics by next generation sequencing. Seven mosquito pools (6.4%) were positive in the flavivirus screening. West Nile virus lineage 1 clade 1a sequences were characterized in a pool Culex pipiens sensu lato specimens, providing the initial virus detection in Aegean region following 2010 outbreak. In an Anopheles maculipennis sensu lato pool, sequences closely-related to Anopheles flaviviruses were obtained, with similarities to several African and Australian strains of this new insect-specific flavivirus clade. In pools comprising Uranotaenia unguiculata (n=3), Cx. pipiens s.l. (n=1) and Aedes caspius (n=1) mosquitoes, sequences of a novel flavivirus, distantly-related to Flavivirus AV2011, identified previously in Spain and Turkey, were characterized. Moreover, DNA forms of the novel flavivirus were detected in two Ur. unguiculata pools. These sequences were highly-similar to the sequences amplified from viral RNA, with undisrupted reading frames, suggest the occurrence of viral DNA forms in natural conditions within mosquito hosts. Rhabdovirus screening revealed sequences of a recently-described novel virus, named the Merida-like virus Turkey (MERDLVT) in 5 Cx. pipiens s.l. pools (4.6%). Partial L and N gene sequences of MERDLVT were well-conserved among strains, with evidence for geographical clustering in phylogenetic analyses. Metagenomics provided the near-full genomic sequence in a specimen, revealing an identical genome organization and limited divergence from the prototype MERDLVT isolate.
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Affiliation(s)
- Ceren Öncü
- Hacettepe University, Faculty of Sciences, Department of Biology, Division of Ecology, Ankara, Turkey
| | - Annika Brinkmann
- Robert Koch Institute, Center for Biological Threats and Special Pathogens 1 (ZBS-1), Berlin, Germany
| | - Filiz Günay
- Hacettepe University, Faculty of Sciences, Department of Biology, Division of Ecology, Ankara, Turkey
| | - Sırrı Kar
- Namık Kemal University, Faculty of Arts and Sciences, Department of Biology, Tekirdağ, Turkey
| | - Kerem Öter
- Istanbul University, Faculty of Veterinary Medicine, Department of Parasitology, Turkey
| | - Yasemen Sarıkaya
- Hacettepe University, Faculty of Sciences, Department of Biology, Division of Ecology, Ankara, Turkey
| | - Andreas Nitsche
- Robert Koch Institute, Center for Biological Threats and Special Pathogens 1 (ZBS-1), Berlin, Germany
| | - Yvonne-Marie Linton
- Walter Reed Biosystematics Unit, Museum Support Center MRC-534, Smithsonian Institution, MD, USA; Department of Entomology, Walter Reed Army Institute of Research, Silver Spring, MD, USA; Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | - Bülent Alten
- Hacettepe University, Faculty of Sciences, Department of Biology, Division of Ecology, Ankara, Turkey
| | - Koray Ergünay
- Robert Koch Institute, Center for Biological Threats and Special Pathogens 1 (ZBS-1), Berlin, Germany; Hacettepe University, Faculty of Medicine, Department of Medical Microbiology, Virology Unit, Ankara, Turkey.
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14
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Shahhosseini N, Chinikar S, Moosa-Kazemi SH, Sedaghat MM, Kayedi MH, Lühken R, Schmidt-Chanasit J. West Nile Virus lineage-2 inCulexspecimens from Iran. Trop Med Int Health 2017; 22:1343-1349. [DOI: 10.1111/tmi.12935] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Nariman Shahhosseini
- Bernhard Nocht Institute for Tropical Medicine; WHO Collaborating Centre for Arbovirus and Hemorrhagic Fever Reference and Research; Hamburg Germany
| | | | - Seyed Hassan Moosa-Kazemi
- Department of Medical Entomology & Vector Control; School of Public Health; Tehran University of Medical Sciences; Tehran Iran
| | - Mohammad Mehdi Sedaghat
- Department of Medical Entomology & Vector Control; School of Public Health; Tehran University of Medical Sciences; Tehran Iran
| | - Mohammad Hassan Kayedi
- Department of Parasitology; School of Medicine; Lorestan University of Medical Sciences; Khorramabad Iran
| | - Renke Lühken
- Bernhard Nocht Institute for Tropical Medicine; WHO Collaborating Centre for Arbovirus and Hemorrhagic Fever Reference and Research; Hamburg Germany
| | - Jonas Schmidt-Chanasit
- Bernhard Nocht Institute for Tropical Medicine; WHO Collaborating Centre for Arbovirus and Hemorrhagic Fever Reference and Research; Hamburg Germany
- German Centre for Infection Research (DZIF); Partner site Hamburg-Luebeck-Borstel; Hamburg Germany
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15
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Hacioglu S, Dincer E, Isler CT, Karapinar Z, Ataseven VS, Ozkul A, Ergunay K. A Snapshot Avian Surveillance Reveals West Nile Virus and Evidence of Wild Birds Participating in Toscana Virus Circulation. Vector Borne Zoonotic Dis 2017; 17:698-708. [PMID: 28832259 DOI: 10.1089/vbz.2017.2138] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
INTRODUCTION Birds are involved in the epidemiology of several vector-borne viruses, as amplification hosts for viruses, dissemination vehicles for the vectors, and sources of emerging strains in cross-species transmission. Turkey provides diverse habitats for a variety of wild birds and is located along major bird migration routes. This study was undertaken to provide a cross-sectional screening of avian specimens for a spectrum of vector-borne viruses. MATERIALS AND METHODS The specimens were collected in Hatay province, in the Mediterranean coast of the Anatolian peninsula, located in the convergence zone of the known migration routes. Generic PCR assays were used for the detection of members of Nairovirus, Flavivirus, and Phlebovirus genera of Flaviviridae and Bunyaviridae families. The circulating viruses were characterized via sequencing and selected specimens were inoculated onto Vero cell lines for virus isolation. RESULTS AND DISCUSSION Specimens from 72 wild birds belonging in 8 orders and 14 species were collected. A total of 158 specimens that comprise 32 sera (20.3%) from 7 species and 126 tissues (79.7%) from 14 species were screened. Eight specimens (8/158, 5%), obtained from 4 individuals (4/72, 5.5%), were positive. West Nile virus (WNV) lineage 1 sequences were characterized in the spleen, heart, and kidney tissues from a lesser spotted eagle (Clanga pomarina), which distinctly clustered from sequences previously identified in Turkey. Toscana virus (TOSV) genotype A and B sequences were identified in brain and kidney tissues from a greater flamingo (Phoenicopterus roseus), a great white pelican (Pelecanus onocrotalus), and a black stork (Ciconia nigra), without successful virus isolation. Partial amino acid sequences of the viral nucleocapsid protein revealed previously unreported substitutions. This study documents the involvement of avians in WNV dispersion in Anatolia as well in TOSV life cycle.
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Affiliation(s)
- Sabri Hacioglu
- 1 Department of Virology, Faculty of Veterinary Medicine, Ankara University , Ankara, Turkey
| | - Ender Dincer
- 2 Advanced Technology Education, Research and Application Center, Mersin University , Mersin, Turkey
| | - Cafer Tayer Isler
- 3 Department of Surgery, Faculty of Veterinary Medicine, Mustafa Kemal University , Hatay, Turkey
| | - Zeynep Karapinar
- 4 Department of Virology, Faculty of Veterinary Medicine, Yuzuncu Yıl University , Van, Turkey
| | - Veysel Soydal Ataseven
- 5 Department of Virology, Faculty of Veterinary Medicine, Mustafa Kemal University , Hatay, Turkey
| | - Aykut Ozkul
- 1 Department of Virology, Faculty of Veterinary Medicine, Ankara University , Ankara, Turkey
| | - Koray Ergunay
- 6 Virology Unit, Department of Medical Microbiology, Faculty of Medicine, Hacettepe University , Ankara, Turkey
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16
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Ergünay K, Litzba N, Brinkmann A, Günay F, Sarıkaya Y, Kar S, Örsten S, Öter K, Domingo C, Erisoz Kasap Ö, Özkul A, Mitchell L, Nitsche A, Alten B, Linton YM. Co-circulation of West Nile virus and distinct insect-specific flaviviruses in Turkey. Parasit Vectors 2017; 10:149. [PMID: 28320443 PMCID: PMC5360070 DOI: 10.1186/s13071-017-2087-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 03/13/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Active vector surveillance provides an efficient tool for monitoring the presence or spread of emerging or re-emerging vector-borne viruses. This study was undertaken to investigate the circulation of flaviviruses. Mosquitoes were collected from 58 locations in 10 provinces across the Aegean, Thrace and Mediterranean Anatolian regions of Turkey in 2014 and 2015. Following morphological identification, mosquitoes were pooled and screened by nested and real-time PCR assays. Detected viruses were further characterised by sequencing. Positive pools were inoculated onto cell lines for virus isolation. Next generation sequencing was employed for genomic characterisation of the isolates. RESULTS A total of 12,711 mosquito specimens representing 15 species were screened in 594 pools. Eleven pools (2%) were reactive in the virus screening assays. Sequencing revealed West Nile virus (WNV) in one Culex pipiens (s.l.) pool from Thrace. WNV sequence corresponded to lineage one clade 1a but clustered distinctly from the Turkish prototype isolate. In 10 pools, insect-specific flaviviruses were characterised as Culex theileri flavivirus in 5 pools of Culex theileri and one pool of Cx. pipiens (s.l.), Ochlerotatus caspius flavivirus in two pools of Aedes (Ochlerotatus) caspius, Flavivirus AV-2011 in one pool of Culiseta annulata, and an undetermined flavivirus in one pool of Uranotaenia unguiculata from the Aegean and Thrace regions. DNA forms or integration of the detected insect-specific flaviviruses were not observed. A virus strain, tentatively named as "Ochlerotatus caspius flavivirus Turkey", was isolated from an Ae. caspius pool in C6/36 cells. The viral genome comprised 10,370 nucleotides with a putative polyprotein of 3,385 amino acids that follows the canonical flavivirus polyprotein organisation. Sequence comparisons and phylogenetic analyses revealed the close relationship of this strain with Ochlerotatus caspius flavivirus from Portugal and Hanko virus from Finland. Several conserved structural and amino acid motifs were identified. CONCLUSIONS We identified WNV and several distinct insect-specific flaviviruses during an extensive biosurveillance study of mosquitoes in various regions of Turkey in 2014 and 2015. Ongoing circulation of WNV is revealed, with an unprecedented genetic diversity. A probable replicating form of an insect flavivirus identified only in DNA form was detected.
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Affiliation(s)
- Koray Ergünay
- Faculty of Medicine, Department of Medical Microbiology, Virology Unit, Hacettepe University, Ankara, Turkey. .,Robert Koch Institute, Center for Biological Threats and Special Pathogens 1 (ZBS-1), Berlin, Germany.
| | - Nadine Litzba
- Robert Koch Institute, Center for Biological Threats and Special Pathogens 1 (ZBS-1), Berlin, Germany
| | - Annika Brinkmann
- Robert Koch Institute, Center for Biological Threats and Special Pathogens 1 (ZBS-1), Berlin, Germany
| | - Filiz Günay
- Faculty of Sciences, Department of Biology, Division of Ecology, Hacettepe University, Ankara, Turkey
| | - Yasemen Sarıkaya
- Faculty of Sciences, Department of Biology, Division of Ecology, Hacettepe University, Ankara, Turkey
| | - Sırrı Kar
- Faculty of Arts and Sciences, Department of Biology, Namık Kemal University, Tekirdağ, Turkey
| | - Serra Örsten
- Faculty of Medicine, Department of Medical Microbiology, Virology Unit, Hacettepe University, Ankara, Turkey
| | - Kerem Öter
- Faculty of Veterinary Medicine, Department of Parasitology, Istanbul University, Istanbul, Turkey
| | - Cristina Domingo
- Robert Koch Institute, Center for Biological Threats and Special Pathogens 1 (ZBS-1), Berlin, Germany
| | - Özge Erisoz Kasap
- Faculty of Sciences, Department of Biology, Division of Ecology, Hacettepe University, Ankara, Turkey
| | - Aykut Özkul
- Department of Virology, Faculty of Veterinary Medicine, Ankara, Turkey
| | - Luke Mitchell
- Walter Reed Biosystematics Unit, Museum Support Center MRC-534, Smithsonian Institution, Maryland, USA
| | - Andreas Nitsche
- Robert Koch Institute, Center for Biological Threats and Special Pathogens 1 (ZBS-1), Berlin, Germany
| | - Bülent Alten
- Faculty of Sciences, Department of Biology, Division of Ecology, Hacettepe University, Ankara, Turkey
| | - Yvonne-Marie Linton
- Walter Reed Biosystematics Unit, Museum Support Center MRC-534, Smithsonian Institution, Maryland, USA.,Department of Entomology, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA.,Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington DC, USA
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17
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Huang B, Prow NA, van den Hurk AF, Allcock RJN, Moore PR, Doggett SL, Warrilow D. Archival Isolates Confirm a Single Topotype of West Nile Virus in Australia. PLoS Negl Trop Dis 2016; 10:e0005159. [PMID: 27906966 PMCID: PMC5131910 DOI: 10.1371/journal.pntd.0005159] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Accepted: 11/03/2016] [Indexed: 11/18/2022] Open
Abstract
West Nile virus is globally wide-spread and causes significant disease in humans and animals. The evolution of West Nile virus Kunjin subtype in Australia (WNVKUN) was investigated using archival samples collected over a period of 50 years. Based on the pattern of fixed amino acid substitutions and time-stamped molecular clock analyses, a single long-term lineage (or topotype) was inferred. This implies that a bottleneck exists such that regional strains eventually die out and are replaced with strains from a single source. This was consistent with current hypotheses regarding the distribution of WNVKUN, whereby the virus is enzootic in northern Australia and is disseminated to southern states by water-birds or mosquitoes after flooding associated with above average rainfall. In addition, two previous amino acid changes associated with pathogenicity, an N-Y-S glycosylation motif in the envelope protein and a phenylalanine at amino acid 653 in the RNA polymerase, were both detected in all isolates collected since the 1980s. Changes primarily occurred due to stochastic drift. One fixed substitution each in NS3 and NS5, subtly changed the chemical environment of important functional groups, and may be involved in fine-tuning RNA synthesis. Understanding these evolutionary changes will help us to better understand events such as the emergence of the virulent strain in 2011. West Nile virus is endemic in Australia, and is considered benign in relation to strains that circulate globally. In 2011, a more pathogenic variant emerged which caused disease in horses. To understand the evolution of the virus, and as a background to the emergence of the pathogenic strain, we used high throughput sequencing combined with bioinformatics tools to obtain an overview of the evolution of the virus over 50 years. A single lineage regardless of the collection site was apparent. This was also supported by the pattern of changes in sequence between the isolates. The most significant finding was that the single lineage nature of the virus’s evolution infers that regional strains circulate for some years before becoming extinct. The regional strains must then be replaced by continual re-seeding, most likely by waterbirds that disseminate the virus across the continent after above average rainfall. There were changes in the nucleotide sequence that had become established at a population level. These were related to the structure of the viral proteins: in particular the envelope protein, the helicase (NS3) and methyltransferase domain of NS5. There were two changes in catalytic domains which may indicate some fine-tuning of replication.
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Affiliation(s)
- Bixing Huang
- Public Health Virology Laboratory, Queensland Health Forensic and Scientific Services, Archerfield, Australia
| | - Natalie A Prow
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Andrew F. van den Hurk
- Public Health Virology Laboratory, Queensland Health Forensic and Scientific Services, Archerfield, Australia
| | - Richard J. N. Allcock
- School of Pathology and Laboratory Medicine, University of Western Australia, Nedlands, Australia
- Translational Cancer Pathology Laboratory, Pathwest Laboratory Medicine WA, QEII Medical Centre, Nedlands, Australia
| | - Peter R. Moore
- Public Health Virology Laboratory, Queensland Health Forensic and Scientific Services, Archerfield, Australia
| | - Stephen L. Doggett
- Department of Medical Entomology, Pathology West–ICPMR, Westmead Hospital, Westmead, Australia
| | - David Warrilow
- Public Health Virology Laboratory, Queensland Health Forensic and Scientific Services, Archerfield, Australia
- * E-mail:
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18
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Fall G, Faye M, Weidmann M, Kaiser M, Dupressoir A, Ndiaye EH, Ba Y, Diallo M, Faye O, Sall AA. Real-Time RT-PCR Assays for Detection and Genotyping of West Nile Virus Lineages Circulating in Africa. Vector Borne Zoonotic Dis 2016; 16:781-789. [PMID: 27710313 DOI: 10.1089/vbz.2016.1967] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
West Nile virus (WNV) is an emerging arbovirus, circulating worldwide between birds and mosquitoes, which impacts human and animal health. Since the mid-1990s, WNV outbreaks have emerged in Europe and America and represent currently the primary cause of encephalitis in the United States. WNV exhibits a great genetic diversity with at least eight different lineages circulating in the world, and four (1, 2, Koutango, and putative new) are present in Africa. These different WNV lineages are not readily differentiated by serology, and thus, rapid molecular tools are required for diagnostic. We developed here real-time RT-PCR assays for detection and genotyping of African WNV lineages. The specificity of the assays was tested using other flaviviruses circulating in Africa. The sensitivity was determined by testing serial 10-fold dilutions of viruses and RNA standards. The assays provided good specificity and sensitivity and the analytical detection limit was 10 copies/reaction. The RT-PCR assays allowed the detection and genotyping of all WNV isolates in culture medium, human serum, and vertebrate tissues, as well as in field and experimental mosquito samples. Comparing the ratios of genome copy number/infectious virion (plaque-forming units), our study finally revealed new insight on the replication of these different WNV lineages in mosquito cells. Our RT-PCR assays are the first ones allowing the genotyping of all WNV African variants, and this may have important applications in surveillance and epidemiology in Africa and also for monitoring of their emergence in Europe and other continents.
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Affiliation(s)
- Gamou Fall
- 1 Unité des Arbovirus et Virus de Fièvres Hémorragiques, Institut Pasteur de Dakar , Dakar, Senegal
| | - Martin Faye
- 1 Unité des Arbovirus et Virus de Fièvres Hémorragiques, Institut Pasteur de Dakar , Dakar, Senegal
| | - Manfred Weidmann
- 2 Institute of Aquaculture, University of Stirling , Stirling, Scotland
| | | | - Anne Dupressoir
- 1 Unité des Arbovirus et Virus de Fièvres Hémorragiques, Institut Pasteur de Dakar , Dakar, Senegal
| | - El Hadj Ndiaye
- 4 Unité d'Entomologie Médicale, Institut Pasteur de Dakar , Dakar, Senegal
| | - Yamar Ba
- 4 Unité d'Entomologie Médicale, Institut Pasteur de Dakar , Dakar, Senegal
| | - Mawlouth Diallo
- 4 Unité d'Entomologie Médicale, Institut Pasteur de Dakar , Dakar, Senegal
| | - Ousmane Faye
- 1 Unité des Arbovirus et Virus de Fièvres Hémorragiques, Institut Pasteur de Dakar , Dakar, Senegal
| | - Amadou Alpha Sall
- 1 Unité des Arbovirus et Virus de Fièvres Hémorragiques, Institut Pasteur de Dakar , Dakar, Senegal
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19
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Recovery of West Nile Virus Envelope Protein Domain III Chimeras with Altered Antigenicity and Mouse Virulence. J Virol 2016; 90:4757-4770. [PMID: 26912625 DOI: 10.1128/jvi.02861-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 02/20/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Flaviviruses are positive-sense, single-stranded RNA viruses responsible for millions of human infections annually. The envelope (E) protein of flaviviruses comprises three structural domains, of which domain III (EIII) represents a discrete subunit. The EIII gene sequence typically encodes epitopes recognized by virus-specific, potently neutralizing antibodies, and EIII is believed to play a major role in receptor binding. In order to assess potential interactions between EIII and the remainder of the E protein and to assess the effects of EIII sequence substitutions on the antigenicity, growth, and virulence of a representative flavivirus, chimeric viruses were generated using the West Nile virus (WNV) infectious clone, into which EIIIs from nine flaviviruses with various levels of genetic diversity from WNV were substituted. Of the constructs tested, chimeras containing EIIIs from Koutango virus (KOUV), Japanese encephalitis virus (JEV), St. Louis encephalitis virus (SLEV), and Bagaza virus (BAGV) were successfully recovered. Characterization of the chimeras in vitro and in vivo revealed differences in growth and virulence between the viruses, within vivo pathogenesis often not being correlated within vitro growth. Taken together, the data demonstrate that substitutions of EIII can allow the generation of viable chimeric viruses with significantly altered antigenicity and virulence. IMPORTANCE The envelope (E) glycoprotein is the major protein present on the surface of flavivirus virions and is responsible for mediating virus binding and entry into target cells. Several viable West Nile virus (WNV) variants with chimeric E proteins in which the putative receptor-binding domain (EIII) sequences of other mosquito-borne flaviviruses were substituted in place of the WNV EIII were recovered, although the substitution of several more divergent EIII sequences was not tolerated. The differences in virulence and tissue tropism observed with the chimeric viruses indicate a significant role for this sequence in determining the pathogenesis of the virus within the mammalian host. Our studies demonstrate that these chimeras are viable and suggest that such recombinant viruses may be useful for investigation of domain-specific antibody responses and the more extensive definition of the contributions of EIII to the tropism and pathogenesis of WNV or other flaviviruses.
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Rizzoli A, Jimenez-Clavero MA, Barzon L, Cordioli P, Figuerola J, Koraka P, Martina B, Moreno A, Nowotny N, Pardigon N, Sanders N, Ulbert S, Tenorio A. The challenge of West Nile virus in Europe: knowledge gaps and research priorities. ACTA ACUST UNITED AC 2015; 20. [PMID: 26027485 DOI: 10.2807/1560-7917.es2015.20.20.21135] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
West Nile virus (WNV) is continuously spreading across Europe, and other continents, i.e. North and South America and many other regions of the world. Despite the overall sporadic nature of outbreaks with cases of West Nile neuroinvasive disease (WNND) in Europe, the spillover events have increased and the virus has been introduced into new areas. The high genetic diversity of the virus, with remarkable phenotypic variation, and its endemic circulation in several countries, require an intensification of the integrated and multidisciplinary research efforts built under the 7th Framework Programme of the European Union (FP7). It is important to better clarify several aspects of WNV circulation in Europe, including its ecology, genomic diversity, pathogenicity, transmissibility, diagnosis and control options, under different environmental and socio-economic scenarios. Identifying WNV endemic as well as infection-free areas is becoming a need for the development of human vaccines and therapeutics and the application of blood and organs safety regulations. This review, produced as a joint initiative among European experts and based on analysis of 118 scientific papers published between 2004 and 2014, provides the state of knowledge on WNV and highlights the existing knowledge and research gaps that need to be addressed with high priority in Europe and neighbouring countries.
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Affiliation(s)
- A Rizzoli
- Fondazione Edmund Mach, Research and Innovation Centre, Department of Biodiversity and Molecular Ecology, San Michele all Adige (TN), Italy
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Ergunay K, Karagul A, Abudalal A, Hacioglu S, Us D, Erdem Y, Ozkul A. Prospective investigation of the impact of West Nile Virus infections in renal diseases. J Med Virol 2015; 87:1625-32. [PMID: 25965349 DOI: 10.1002/jmv.24226] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/01/2015] [Indexed: 11/06/2022]
Abstract
An increased incidence of chronic kidney disease (CKD) after West Nile Virus (WNV) infections has been suggested but the association of WNV infections with renal damage remain inconclusive. This study was undertaken to characterize WNV infections in individuals with acute kidney injury (AKI) and CKD, and to evaluate hemodialysis as a probable transmission route. A total of 463 plasma and urine samples were collected from 45 AKI and 77 CKD patients. Nested and real-time polymerase chain reaction (PCR) assays were employed for viral RNA detection. Specific immunoglobulins were investigated via immunofluorescence and plaque reduction neutralization assays. Consecutive pre and post-dialysis samples were evaluated in CKD cases. WNV RNA and specific immunoglobulins were detected in 7 (5.7%) and 5 (4.1%) individuals, respectively. The AKI patients with WNV RNA in blood and urine had underlying diseases requiring immunosuppressive therapy and demonstrated moderate to high viral loads. No clinical symptom related to WNV infection were observed in CKD cases with detectable viral nucleic acids. All WNV sequences were characterized as lineage 1 clade 1a and several amino acid substitutions with unknown impact were noted. Detailed epidemiologic investigation of WNV RNA positive CKD cases revealed probable vector-borne virus exposure, without the evidence for transmission via hemodialysis.
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Affiliation(s)
- Koray Ergunay
- Department of Medical Microbiology, Hacettepe University; Faculty of Medicine, Ankara, Turkey
| | - Aydan Karagul
- Department of Medical Microbiology, Hacettepe University; Faculty of Medicine, Ankara, Turkey
| | - Ayman Abudalal
- Division of Nephrology, Department of Internal Medicine, Hacettepe University; Faculty of Medicine, Ankara, Turkey
| | - Sabri Hacioglu
- Department of Virology, Ankara University; Faculty of Veterinary Medicine, Ankara, Turkey
| | - Durdal Us
- Department of Medical Microbiology, Hacettepe University; Faculty of Medicine, Ankara, Turkey
| | - Yunus Erdem
- Division of Nephrology, Department of Internal Medicine, Hacettepe University; Faculty of Medicine, Ankara, Turkey
| | - Aykut Ozkul
- Department of Virology, Ankara University; Faculty of Veterinary Medicine, Ankara, Turkey
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