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Mbaoma OC, Thomas SM, Beierkuhnlein C. Spatiotemporally Explicit Epidemic Model for West Nile Virus Outbreak in Germany: An Inversely Calibrated Approach. J Epidemiol Glob Health 2024; 14:1052-1070. [PMID: 38965178 PMCID: PMC11442818 DOI: 10.1007/s44197-024-00254-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 05/29/2024] [Indexed: 07/06/2024] Open
Abstract
Since the first autochthonous transmission of West Nile Virus was detected in Germany (WNV) in 2018, it has become endemic in several parts of the country and is continuing to spread due to the attainment of a suitable environment for vector occurrence and pathogen transmission. Increasing temperature associated with a changing climate has been identified as a potential driver of mosquito-borne disease in temperate regions. This scenario justifies the need for the development of a spatially and temporarily explicit model that describes the dynamics of WNV transmission in Germany. In this study, we developed a process-based mechanistic epidemic model driven by environmental and epidemiological data. Functional traits of mosquitoes and birds of interest were used to parameterize our compartmental model appropriately. Air temperature, precipitation, and relative humidity were the key climatic forcings used to replicate the fundamental niche responsible for supporting mosquito population and infection transmission risks in the study area. An inverse calibration method was used to optimize our parameter selection. Our model was able to generate spatially and temporally explicit basic reproductive number (R0) maps showing dynamics of the WNV occurrences across Germany, which was strongly associated with the deviation from daily means of climatic forcings, signaling the impact of a changing climate in vector-borne disease dynamics. Epidemiological data for human infections sourced from Robert Koch Institute and animal cases collected from the Animal Diseases Information System (TSIS) of the Friedrich-Loeffler-Institute were used to validate model-simulated transmission rates. From our results, it was evident that West Nile Virus is likely to spread towards the western parts of Germany with the rapid attainment of environmental suitability for vector mosquitoes and amplifying host birds, especially short-distance migratory birds. Locations with high risk of WNV outbreak (Baden-Württemberg, Bavaria, Berlin, Brandenburg, Hamburg, North Rhine-Westphalia, Rhineland-Palatinate, Saarland, Saxony-Anhalt and Saxony) were shown on R0 maps. This study presents a path for developing an early warning system for vector-borne diseases driven by climate change.
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Affiliation(s)
- Oliver Chinonso Mbaoma
- Department of Biogeography, University of Bayreuth, Universitaetsstr. 30, 95447, Bayreuth, Germany.
| | - Stephanie Margarete Thomas
- Department of Biogeography, University of Bayreuth, Universitaetsstr. 30, 95447, Bayreuth, Germany
- Bayreuth Center of Ecology and Environmental Research, BayCEER, University of Bayreuth, Universitaetsstr. 30, 95447, Bayreuth, Germany
| | - Carl Beierkuhnlein
- Department of Biogeography, University of Bayreuth, Universitaetsstr. 30, 95447, Bayreuth, Germany
- Bayreuth Center of Ecology and Environmental Research, BayCEER, University of Bayreuth, Universitaetsstr. 30, 95447, Bayreuth, Germany
- Geographical Institute of the University of Bayreuth, GIB, Universitaetsstr. 30, 95447, Bayreuth, Germany
- Departamento de Botánico, Universidad de Granada, 18071, Granada, Spain
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Megenas JA, Dadi ML, Mekonnen TK, Larrick JW, Kassa GM. Seroprevalence and Co-Circulation of Rift Valley Fever Virus and West Nile Fever Virus in Livestock Population of Afar Region, Northeast Ethiopia. Vet Med Int 2024; 2024:8249077. [PMID: 39224542 PMCID: PMC11368548 DOI: 10.1155/2024/8249077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 07/23/2024] [Accepted: 08/05/2024] [Indexed: 09/04/2024] Open
Abstract
The distribution, epidemiology, and socioeconomic impact of Rift Valley fever (RVF) and West Nile (WN) viruses are poorly known in areas of sub-Saharan countries like Ethiopian pastoral region. The human and livestock density in the area has increased greatly in recent years, but little work has been done on arboviral diseases and their potential impact on human and livestock health. The aim of this study was to detect the circulation of zoonotic arboviruses such as Rift Valley fever virus and West Nile viruses in the livestock population and to estimate seroprevalence in Afar pastoral area northeast Ethiopia. Cross-sectional serological survey was carried out in 736 serum samples from which cattle (224), camel (155), goats (121), sheep (144), and donkeys (92) were tested for the presence of anti-RVFV and anti-WNV IgG using a competitive enzyme-linked immunosorbent assay (c-ELISA) in two purposively selected districts of the Afar region. The present study revealed a 9.1% (95% CI = 8.86-9.29) seroprevalence of co-circulation of RVF and WNV. High 32/155 (20.7%) seroprevalence of co-circulation was seen in camels, followed by goat 14/121 (11.6%), cattle 16/224 (7.14%), and sheep 5/144 (3.5%), respectively, and higher 41/421 (9.7%) seroprevalence of co-circulation was observed in Amibara district than Haruka district. Camels were seven times (OR: 7.016, 95% CI = 2.639-18.653) more likely to be seropositive for the co-circulation than sheep (p ≤ 0.001). Livestock herds found in Amibara district were 1.2 times (OR: 1.165, 95% CI = 0.680-1.996) more likely to be seropositive for RVFV infection than those in Haruka areas. Given the co-occurrence of RVFV and WNV circulations, along with often suboptimal human and animal health surveillance in many similar areas' attention should be given. Investigation of the potential socioeconomic and health impacts of zoonotic arbovirus infections in such areas is crucial. Since both RVFV and WNFV are transmitted through a mosquito vector, avoiding mosquito bites is the primary method of prevention.
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Affiliation(s)
- Jemberu Alemu Megenas
- Department of Veterinary MicrobiologyImmunology and Public HealthCollege of Veterinary MedicineAddis Ababa University, Bishoftu, Ethiopia
- College of Agriculture and Natural ResourcesGambella University, Gambella, Ethiopia
| | | | - Tesfu Kassa Mekonnen
- Aklilu Lemma Institute of PathobiologyAddis Ababa University, Addis Ababa, Ethiopia
| | | | - Gezahegne Mamo Kassa
- Department of Veterinary MicrobiologyImmunology and Public HealthCollege of Veterinary MedicineAddis Ababa University, Bishoftu, Ethiopia
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Fiacre L, Nougairède A, Migné C, Bayet M, Cochin M, Dumarest M, Helle T, Exbrayat A, Pagès N, Vitour D, Richardson JP, Failloux AB, Vazeille M, Albina E, Lecollinet S, Gonzalez G. Different viral genes modulate virulence in model mammal hosts and Culex pipiens vector competence in Mediterranean basin lineage 1 West Nile virus strains. Front Microbiol 2024; 14:1324069. [PMID: 38298539 PMCID: PMC10828019 DOI: 10.3389/fmicb.2023.1324069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 12/28/2023] [Indexed: 02/02/2024] Open
Abstract
West Nile virus (WNV) is a single-stranded positive-sense RNA virus (+ssRNA) belonging to the genus Orthoflavivirus. Its enzootic cycle involves mosquito vectors, mainly Culex, and wild birds as reservoir hosts, while mammals, such as humans and equids, are incidental dead-end hosts. It was first discovered in 1934 in Uganda, and since 1999 has been responsible for frequent outbreaks in humans, horses and wild birds, mostly in America and in Europe. Virus spread, as well as outbreak severity, can be influenced by many ecological factors, such as reservoir host availability, biodiversity, movements and competence, mosquito abundance, distribution and vector competence, by environmental factors such as temperature, land use and precipitation, as well as by virus genetic factors influencing virulence or transmission. Former studies have investigated WNV factors of virulence, but few have compared viral genetic determinants of pathogenicity in different host species, and even fewer have considered the genetic drivers of virus invasiveness and excretion in Culex vector. In this study, we characterized WNV genetic factors implicated in the difference in virulence observed in two lineage 1 WNV strains from the Mediterranean Basin, the first isolated during a significant outbreak reported in Israel in 1998, and the second from a milder outbreak in Italy in 2008. We used an innovative and powerful reverse genetic tool, e.g., ISA (infectious subgenomic amplicons) to generate chimeras between Israel 1998 and Italy 2008 strains, focusing on non-structural (NS) proteins and the 3'UTR non-coding region. We analyzed the replication of these chimeras and their progenitors in mammals, in BALB/cByJ mice, and vector competence in Culex (Cx.) pipiens mosquitoes. Results obtained in BALB/cByJ mice suggest a role of the NS2B/NS3/NS4B/NS5 genomic region in viral attenuation in mammals, while NS4B/NS5/3'UTR regions are important in Cx. pipiens infection and possibly in vector competence.
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Affiliation(s)
- Lise Fiacre
- UMR VIRO, ANSES, ENVA, INRAE Virologie, Laboratoire de Santé Animale, Maisons-Alfort, France
- UMR ASTRE, CIRAD, Petit-Bourg, Guadeloupe
| | - Antoine Nougairède
- Unité Des Virus Emergents (UVE), Aix-Marseille Université, IRD 190, INSERM 1207, Marseille, France
| | - Camille Migné
- UMR VIRO, ANSES, ENVA, INRAE Virologie, Laboratoire de Santé Animale, Maisons-Alfort, France
| | | | - Maxime Cochin
- Unité Des Virus Emergents (UVE), Aix-Marseille Université, IRD 190, INSERM 1207, Marseille, France
| | - Marine Dumarest
- UMR VIRO, ANSES, ENVA, INRAE Virologie, Laboratoire de Santé Animale, Maisons-Alfort, France
| | - Teheipuaura Helle
- UMR VIRO, ANSES, ENVA, INRAE Virologie, Laboratoire de Santé Animale, Maisons-Alfort, France
| | - Antoni Exbrayat
- ASTRE, CIRAD, INRAe, Université de Montpellier, Montpellier, France
| | | | - Damien Vitour
- UMR VIRO, ANSES, ENVA, INRAE Virologie, Laboratoire de Santé Animale, Maisons-Alfort, France
| | - Jennifer P. Richardson
- UMR VIRO, ANSES, ENVA, INRAE Virologie, Laboratoire de Santé Animale, Maisons-Alfort, France
| | - Anna-Bella Failloux
- Institut Pasteur, Université Paris Cité, Arboviruses and Insects Vectors, Paris, France
| | - Marie Vazeille
- Institut Pasteur, Université Paris Cité, Arboviruses and Insects Vectors, Paris, France
| | - Emmanuel Albina
- ASTRE, CIRAD, INRAe, Université de Montpellier, Montpellier, France
| | | | - Gaëlle Gonzalez
- UMR VIRO, ANSES, ENVA, INRAE Virologie, Laboratoire de Santé Animale, Maisons-Alfort, France
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Rau J, Köchling K, Schäfer M, Tews BA, Wylezich C, Schaub GA, Werner D, Kampen H. Viral RNA in Mosquitoes (Diptera: Culicidae) Collected between 2019 and 2021 in Germany. Viruses 2023; 15:2298. [PMID: 38140539 PMCID: PMC10746995 DOI: 10.3390/v15122298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 11/18/2023] [Accepted: 11/20/2023] [Indexed: 12/24/2023] Open
Abstract
Due to globalisation and climate change, mosquito-borne pathogens are emerging in new areas on all continents, including Europe, which has recently faced outbreaks of dengue, chikungunya and West Nile fever. The present study complements previous investigations to evaluate the circulation of mosquito-borne viruses in Germany, with the aim of identifying potential vector species and risk areas. Mosquitoes collected from 2019 to 2021 and identified to species or species group level were screened for viruses of the families Flaviviridae, Peribunyaviridae and the genus Alphavirus of the family Togaviridae. In total, 22,528 mosquitoes were examined, thus providing the most comprehensive study on West Nile virus (WNV) circulation so far in the German mosquito population. Usutu virus (USUV) RNA was detected in six samples, Sindbis virus (SINV) RNA in 21 samples and WNV RNA in 11 samples. Samples containing RNA of USUV and WNV consisted of mosquitoes collected in the East German federal states of Brandenburg, Saxony and Saxony-Anhalt, while samples with RNA of SINV originated from more widespread locations. Although minimum infection rates have remained relatively low, the intensity of virus circulation appears to be increasing compared to previous studies. Continuous mosquito screening contributes to the early detection of the introduction and spread of mosquito-borne pathogens.
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Affiliation(s)
- Janine Rau
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald, Germany; (M.S.); (B.A.T.); (C.W.); (H.K.)
| | - Katharina Köchling
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald, Germany; (M.S.); (B.A.T.); (C.W.); (H.K.)
| | - Mandy Schäfer
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald, Germany; (M.S.); (B.A.T.); (C.W.); (H.K.)
| | - Birke A. Tews
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald, Germany; (M.S.); (B.A.T.); (C.W.); (H.K.)
| | - Claudia Wylezich
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald, Germany; (M.S.); (B.A.T.); (C.W.); (H.K.)
| | - Günter A. Schaub
- Zoology/Parasitology Department, Ruhr-University, Universitätsstr. 150, 44801 Bochum, Germany;
| | - Doreen Werner
- Leibniz Centre for Agricultural Landscape Research, Eberswalder Str. 84, 15374 Müncheberg, Germany;
| | - Helge Kampen
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald, Germany; (M.S.); (B.A.T.); (C.W.); (H.K.)
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5
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Ruscher C, Patzina-Mehling C, Melchert J, Graff SL, McFarland SE, Hieke C, Kopp A, Prasser A, Tonn T, Schmidt M, Isner C, Drosten C, Werber D, Corman VM, Junglen S. Ecological and clinical evidence of the establishment of West Nile virus in a large urban area in Europe, Berlin, Germany, 2021 to 2022. Euro Surveill 2023; 28:2300258. [PMID: 38037727 PMCID: PMC10690859 DOI: 10.2807/1560-7917.es.2023.28.48.2300258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 09/14/2023] [Indexed: 12/02/2023] Open
Abstract
BackgroundWest Nile virus (WNV), found in Berlin in birds since 2018 and humans since 2019, is a mosquito-borne virus that can manifest in humans as West Nile fever (WNF) or neuroinvasive disease (WNND). However, human WNV infections and associated disease are likely underdiagnosed.AimWe aimed to identify and genetically characterise WNV infections in humans and mosquitoes in Berlin.MethodsWe investigated acute WNV infection cases reported to the State Office for Health and Social Affairs Berlin in 2021 and analysed cerebrospinal fluid (CSF) samples from patients with encephalitis of unknown aetiology (n = 489) for the presence of WNV. Mosquitoes were trapped at identified potential exposure sites of cases and examined for WNV infection.ResultsWest Nile virus was isolated and sequenced from a blood donor with WNF, a symptomatic patient with WNND and a WNND case retrospectively identified from testing CSF. All cases occurred in 2021 and had no history of travel 14 days prior to symptom onset (incubation period of the disease). We detected WNV in Culex pipiens mosquitoes sampled at the exposure site of one case in 2021, and in 2022. Genome analyses revealed a monophyletic Berlin-specific virus clade in which two enzootic mosquito-associated variants can be delineated based on tree topology and presence of single nucleotide variants. Both variants have highly identical counterparts in human cases indicating local acquisition of infection.ConclusionOur study provides evidence that autochthonous WNV lineage 2 infections occurred in Berlin and the virus has established an endemic maintenance cycle.
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Affiliation(s)
- Claudia Ruscher
- State Office for Health and Social Affairs (SOHSA), Berlin, Germany
| | - Corinna Patzina-Mehling
- Institute of Virology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Julia Melchert
- German Centre for Infection Research (DZIF), partner site Charité, Berlin, Germany
- Institute of Virology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Selina L Graff
- Institute of Virology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | | | - Christian Hieke
- Institute of Virology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Anne Kopp
- Institute of Virology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Anita Prasser
- State Office for Health and Social Affairs (SOHSA), Berlin, Germany
| | - Torsten Tonn
- Experimentelle Transfusionsmedizin, Medical Faculty Carl Gustav Carus, TU Dresden and Institute for Transfusion Medicine Dresden, DRK Blutspendedienst Nord-Ost, Dresden, Germany
| | - Michael Schmidt
- Experimentelle Transfusionsmedizin, Medical Faculty Carl Gustav Carus, TU Dresden and Institute for Transfusion Medicine Dresden, DRK Blutspendedienst Nord-Ost, Dresden, Germany
| | - Caroline Isner
- Department of Infectious Diseases, Vivantes Auguste-Viktoria-Klinikum, Berlin, Germany
| | - Christian Drosten
- German Centre for Infection Research (DZIF), partner site Charité, Berlin, Germany
- Institute of Virology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Dirk Werber
- State Office for Health and Social Affairs (SOHSA), Berlin, Germany
| | - Victor M Corman
- Labor Berlin - Charité Vivantes GmbH, Berlin, Germany
- German Centre for Infection Research (DZIF), partner site Charité, Berlin, Germany
- Institute of Virology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Sandra Junglen
- Institute of Virology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
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Bergmann F, Holicki CM, Michel F, Bock S, Scuda N, Priemer G, Kenklies S, Siempelkamp T, Skuballa J, Sauerwald C, Herms L, Muluneh A, Peters M, Hlinak A, Groschup MH, Sadeghi B, Ziegler U. Reconstruction of the molecular evolution of Usutu virus in Germany: Insights into virus emersion and circulation. PLoS Negl Trop Dis 2023; 17:e0011203. [PMID: 37782665 PMCID: PMC10569574 DOI: 10.1371/journal.pntd.0011203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 10/12/2023] [Accepted: 09/07/2023] [Indexed: 10/04/2023] Open
Abstract
Usutu virus (USUV) is a mosquito-borne flavivirus that is widely distributed in southern and central Europe. The zoonotic virus circulates primarily between birds and mosquitoes, can, however, in rare cases infect other mammals including humans. In the past, USUV has been repeatedly associated with mass mortalities in birds, primarily blackbirds and owls. Birds commonly succumb either due to the peracute nature of the infection or due to severe encephalitis. In Germany, USUV has spread rapidly since its first detection in 2010 in mosquitoes under the presence of susceptible host and vector species. Nonetheless, there is to date limited access to whole genome sequences resulting in the absence of in-depth phylogenetic and phylodynamic analyses. In this study, 118 wild and captive birds were sequenced using a nanopore sequencing platform with prior target enrichment via amplicons. Due to the high abundancy of Europe 3 and Africa 3 in Germany an ample quantity of associated whole genome sequences was generated and the most recent common ancestor could be determined for each lineage. The corresponding clock phylogeny revealed an introduction of USUV Europe 3 and Africa 3 into Germany three years prior to their first isolation in the avifauna in 2011 and 2014, respectively. Based on the clustering and temporal history of the lineages, evidence exists for the genetic evolution of USUV within Germany as well as new introductions thereof into the country.
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Affiliation(s)
- Felicitas Bergmann
- Institute of Novel and Emerging Infectious Disease, Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Cora M. Holicki
- Institute of Novel and Emerging Infectious Disease, Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Friederike Michel
- Institute of Novel and Emerging Infectious Disease, Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Sabine Bock
- Berlin-Brandenburg State Laboratory, Frankfurt (Oder), Germany
| | - Nelly Scuda
- Bavarian Health and Food Safety Authority, Erlangen, Germany
| | - Grit Priemer
- State Office of Agriculture, Food Safety and Fisheries Mecklenburg-Vorpommern (LALLF), Rostock, Germany
| | - Susanne Kenklies
- State Office for Consumer Protection Saxony-Anhalt (LAV), Stendal, Germany
| | - Timo Siempelkamp
- Thuringian State Office for Consumer Protection, Bad Langensalza, Germany
| | - Jasmin Skuballa
- State Institute for Chemical and Veterinary Analysis Karlsruhe, Karlsruhe, Germany
| | - Claudia Sauerwald
- Department of Veterinary Medicine, Hessian State Laboratory, Gießen, Germany
| | - Louise Herms
- Lower Saxony State Office for Consumer Protection and Food Safety (LAVES), Hannover, Germany
| | - Aemero Muluneh
- Saxon State Laboratory of Health and Veterinary Affairs, Dresden, Germany
| | - Martin Peters
- Chemical and Veterinary Investigation Office (CVUA), Arnsberg, Germany
| | - Andreas Hlinak
- Berlin-Brandenburg State Laboratory, Frankfurt (Oder), Germany
| | - Martin H. Groschup
- Institute of Novel and Emerging Infectious Disease, Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
- German Center of Infection Research (DZIF), Partner site Hamburg-Lübeck-Borstel-Riems, Greifswald-Insel Riems, Germany
| | - Balal Sadeghi
- Institute of Novel and Emerging Infectious Disease, Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Ute Ziegler
- Institute of Novel and Emerging Infectious Disease, Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
- German Center of Infection Research (DZIF), Partner site Hamburg-Lübeck-Borstel-Riems, Greifswald-Insel Riems, Germany
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Natasha JA, Yasmin AR, Kumar Sharma RS, Nur-Fazila SH, Nur-Mahiza MI, Arshad SS, Mohammed HO, Kumar K, Keng Loong S, Ahmad Khusaini MKS. Mosquito as West Nile Virus Vector: Global Timeline of Detection, Characteristic, and Biology. PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE 2023; 46:1063-1081. [DOI: 10.47836/pjtas.46.3.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Mosquitoes are extremely important vectors that transmit zoonotic West Nile virus (WNV) globally, resulting in significant outbreaks in birds, humans, and mammals. The abundance of mosquito vectors combined with the migratory flying behaviour of wild birds across the globe has exacerbated the dynamics of WNV infection. Depth understanding of the WNV infection requires a comprehensive understanding of the character of the vector in terms of their taxonomy, morphology, biology, behaviours, preferences, and factors that promote their breeding. Most susceptible animals and humans may experience serious neurological illnesses such as encephalitis. Little is known about the susceptibility of mosquitoes to WNV infection. This review provides insightful knowledge about the characteristics of mosquitoes that carry WNV and their susceptibility to WNV infection. The context of mosquito’s involvement in WNV transmission is demonstrated through space and time from the 1950’s until to date. The historical timeline of WNV transmission strength was significantly intensified via the complex interactions between vector, virus, and environment. Such knowledge will provide valuable insights into vector control intervention mitigation strategies, especially in tropical climate countries like Malaysia.
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Körsten C, Vasić A, AL-Hosary AA, Tews BA, Răileanu C, Silaghi C, Schäfer M. Excretion Dynamics of Arboviruses in Mosquitoes and the Potential Use in Vector Competence Studies and Arbovirus Surveillance. Trop Med Infect Dis 2023; 8:410. [PMID: 37624347 PMCID: PMC10459540 DOI: 10.3390/tropicalmed8080410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/19/2023] [Accepted: 08/04/2023] [Indexed: 08/26/2023] Open
Abstract
The increasing threat of arboviruses such as West Nile virus (WNV) and Usutu virus (USUV) requires the fast and efficient surveillance of these viruses. The examination of mosquitoes takes up an important part; however, these investigations are usually very time-consuming. An alternative sample type for arbovirus surveillance might be mosquito excreta. In order to determine the excretion dynamics under laboratory conditions, laboratory colonies of Aedes vexans and Culex pipiens biotype molestus were infected with WNV, USUV or tick-borne encephalitis virus (TBEV). After infection, the excreta were sampled and investigated for viral RNA. Excretion of viral RNA together with infectious blood meal could be detected up to five days after infection. Further excretion seemed to correlate with a disseminated infection in mosquitoes, at least after USUV infection. In addition, it could be determined that the amount of viral RNA in the excretions correlated positively with the viral load in the mosquito bodies. Overall, this study shows that the usage of mosquito excreta as a sample type for surveillance enables the detection of endemic viruses (WNV, USUV) as well as non-mosquito-borne viruses (TBEV). In addition, examination of viral shedding during vector competence studies can provide insights into the course of infection without sacrificing animals.
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Affiliation(s)
- Christin Körsten
- Institute of Infectology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, 17493 Greifswald, Germany; (C.K.)
| | - Ana Vasić
- Institute of Infectology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, 17493 Greifswald, Germany; (C.K.)
- Scientific Institute of Veterinary Medicine of Serbia, 11000 Belgrade, Serbia
| | - Amira A. AL-Hosary
- Institute of Infectology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, 17493 Greifswald, Germany; (C.K.)
- Department of Animal Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Assiut University, Assiut 71526, Egypt
| | - Birke A. Tews
- Institute of Infectology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, 17493 Greifswald, Germany; (C.K.)
| | - Cristian Răileanu
- Institute of Infectology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, 17493 Greifswald, Germany; (C.K.)
| | - Cornelia Silaghi
- Institute of Infectology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, 17493 Greifswald, Germany; (C.K.)
| | - Mandy Schäfer
- Institute of Infectology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, 17493 Greifswald, Germany; (C.K.)
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Reemtsma H, Holicki CM, Fast C, Bergmann F, Groschup MH, Ziegler U. A Prior Usutu Virus Infection Can Protect Geese from Severe West Nile Disease. Pathogens 2023; 12:959. [PMID: 37513806 PMCID: PMC10386565 DOI: 10.3390/pathogens12070959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/13/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
Usutu virus (USUV) and West Nile virus (WNV) are closely related pathogens circulating between mosquitoes and birds, but also infecting mammals as dead-end hosts. Both viruses share the same susceptible hosts, vectors, and even distribution areas in Central Europe. The aim of the study was, therefore, to understand their amplification potential and interference upon a successive infection. Two-week old geese were initially infected with an USUV isolate from Germany and with a German WNV isolate17 days later. The geese were susceptible to the USUV and the WNV infections, as evidenced by specific flavivirus antibodies in all of the birds. Furthermore, in half of the USUV-inoculated geese, USUV genomes were detected in the blood and swab samples 2-4 days post-infection. Additionally, most of the examined organs contained USUV genomes and showed signs of encephalitis and ganglioneuritis. Interestingly, upon a sequential infection with WNV, the genome copy numbers in all of the examined samples were significantly lower and less frequent than after a WNV mono-infection. Similarly, the histopathological lesions were less severe. Therefore, it can be concluded that a previous USUV infection can protect birds from clinical disease in a subsequent WNV infection.
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Affiliation(s)
- Hannah Reemtsma
- Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, 17493 Greifswald-Insel Riems, Germany
| | - Cora M Holicki
- Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, 17493 Greifswald-Insel Riems, Germany
| | - Christine Fast
- Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, 17493 Greifswald-Insel Riems, Germany
| | - Felicitas Bergmann
- Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, 17493 Greifswald-Insel Riems, Germany
| | - Martin H Groschup
- Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, 17493 Greifswald-Insel Riems, Germany
| | - Ute Ziegler
- Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, 17493 Greifswald-Insel Riems, Germany
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10
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Beermann S, Dobler G, Faber M, Frank C, Habedank B, Hagedorn P, Kampen H, Kuhn C, Nygren T, Schmidt-Chanasit J, Schmolz E, Stark K, Ulrich RG, Weiss S, Wilking H. Impact of climate change on vector- and rodent-borne infectious diseases. JOURNAL OF HEALTH MONITORING 2023; 8:33-61. [PMID: 37342429 PMCID: PMC10278376 DOI: 10.25646/11401] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 01/10/2023] [Indexed: 06/22/2023]
Abstract
Background Endemic and imported vector- and rodent-borne infectious agents can be linked to high morbidity and mortality. Therefore, vector- and rodent-borne human diseases and the effects of climate change are important public health issues. Methods For this review, the relevant literature was identified and evaluated according to the thematic aspects and supplemented with an analysis of surveillance data for Germany. Results Factors such as increasing temperatures, changing precipitation patterns, and human behaviour may influence the epidemiology of vector- and rodent-borne infectious diseases in Germany. Conclusions The effects of climatic changes on the spread of vector- and rodent-borne infectious diseases need to be further studied in detail and considered in the context of climate adaptation measures.
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Affiliation(s)
| | - Gerhard Dobler
- Bundeswehr Institute of Microbiology, Munich, Germany, National Consulting Laboratory for Tick-Borne Encephalitis
| | - Mirko Faber
- Robert Koch Institute, Berlin, Germany Department of Infectious Disease Epidemiology
| | - Christina Frank
- Robert Koch Institute, Berlin, Germany Department of Infectious Disease Epidemiology
| | - Birgit Habedank
- German Environment Agency, Berlin, Germany, Section IV 1.4 Health Pests and their Control
| | - Peter Hagedorn
- Robert Koch Institute, Berlin, Germany Centre for Biological Threats and Special Pathogens
| | - Helge Kampen
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany, Institute of Infectology
| | - Carola Kuhn
- German Environment Agency, Berlin, Germany, Section IV 1.4 Health Pests and their Control
| | - Teresa Nygren
- Robert Koch Institute, Berlin, Germany Department of Infectious Disease Epidemiology
| | - Jonas Schmidt-Chanasit
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany, Arbovirus and Entomology Department
| | - Erik Schmolz
- German Environment Agency, Berlin, Germany, Section IV 1.4 Health Pests and their Control
| | - Klaus Stark
- Robert Koch Institute, Berlin, Germany Department of Infectious Disease Epidemiology
| | - Rainer G. Ulrich
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany, Institute of Novel and Emerging Infectious Diseases
- German Center for Infection Research Greifswald - Insel Riems, Germany
| | - Sabrina Weiss
- Robert Koch Institute, Berlin, Germany Centre for International Health Protection
| | - Hendrik Wilking
- Robert Koch Institute, Berlin, Germany Department of Infectious Disease Epidemiology
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11
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Ulrich RG, Drewes S, Haring V, Panajotov J, Pfeffer M, Rubbenstroth D, Dreesman J, Beer M, Dobler G, Knauf S, Johne R, Böhmer MM. [Viral zoonoses in Germany: a One Health perspective]. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2023; 66:599-616. [PMID: 37261460 PMCID: PMC10233563 DOI: 10.1007/s00103-023-03709-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 04/26/2023] [Indexed: 06/02/2023]
Abstract
The COVID-19 pandemic and the increasing occurrence of monkeypox (mpox) diseases outside Africa have illustrated the vulnerability of populations to zoonotic pathogens. In addition, other viral zoonotic pathogens have gained importance in recent years.This review article addresses six notifiable viral zoonotic pathogens as examples to highlight the need for the One Health approach in order to understand the epidemiology of the diseases and to derive recommendations for action by the public health service. The importance of environmental factors, reservoirs, and vectors is emphasized, the diseases in livestock and wildlife are analyzed, and the occurrence and frequency of diseases in the population are described. The pathogens selected here differ in their reservoirs and the role of vectors for transmission, the impact of infections on farm animals, and the disease patterns observed in humans. In addition to zoonotic pathogens that have been known in Germany for a long time or were introduced recently, pathogens whose zoonotic potential has only lately been shown are also considered.For the pathogens discussed here, there are still large knowledge gaps regarding the transmission routes. Future One Health-based studies must contribute to the further elucidation of their transmission routes and the development of prevention measures. The holistic approach does not necessarily include a focus on viral pathogens/diseases, but also includes the question of the interaction of viral, bacterial, and other pathogens, including antibiotic resistance and host microbiomes.
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Affiliation(s)
- Rainer G Ulrich
- Institut für neue und neuartige Tierseuchenerreger, Friedrich-Loeffler-Institut, Bundesforschungsinstitut für Tiergesundheit, Südufer 10, 17493, Greifswald-Insel Riems, Deutschland.
| | - Stephan Drewes
- Institut für neue und neuartige Tierseuchenerreger, Friedrich-Loeffler-Institut, Bundesforschungsinstitut für Tiergesundheit, Südufer 10, 17493, Greifswald-Insel Riems, Deutschland
| | - Viola Haring
- Institut für neue und neuartige Tierseuchenerreger, Friedrich-Loeffler-Institut, Bundesforschungsinstitut für Tiergesundheit, Südufer 10, 17493, Greifswald-Insel Riems, Deutschland
| | - Jessica Panajotov
- Fachgruppe Viren in Lebensmitteln, Bundesinstitut für Risikobewertung, Berlin, Deutschland
| | - Martin Pfeffer
- Institut für Tierhygiene und Öffentliches Veterinärwesen, Universität Leipzig, Leipzig, Deutschland
| | - Dennis Rubbenstroth
- Institut für Virusdiagnostik, Friedrich-Loeffler-Institut, Bundesforschungsinstitut für Tiergesundheit, Greifswald-Insel Riems, Deutschland
| | | | - Martin Beer
- Institut für Virusdiagnostik, Friedrich-Loeffler-Institut, Bundesforschungsinstitut für Tiergesundheit, Greifswald-Insel Riems, Deutschland
| | - Gerhard Dobler
- Abteilung Virologie und Rickettsiologie, Institut für Mikrobiologie der Bundeswehr, München, Deutschland
| | - Sascha Knauf
- Institut für Internationale Tiergesundheit/One Health, Friedrich-Loeffler-Institut, Bundesforschungsinstitut für Tiergesundheit, Greifswald-Insel Riems, Deutschland
| | - Reimar Johne
- Fachgruppe Viren in Lebensmitteln, Bundesinstitut für Risikobewertung, Berlin, Deutschland
| | - Merle M Böhmer
- Landesinstitut Gesundheit II - Task Force Infektiologie, Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit (LGL), München, Deutschland
- Institut für Sozialmedizin und Gesundheitssystemforschung, Otto-von-Guericke Universität, Magdeburg, Deutschland
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12
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Körsten C, Al-Hosary AA, Holicki CM, Schäfer M, Tews BA, Vasić A, Ziegler U, Groschup MH, Silaghi C. Simultaneous Coinfections with West Nile Virus and Usutu Virus in Culex pipiens and Aedes vexans Mosquitoes. Transbound Emerg Dis 2023. [DOI: 10.1155/2023/6305484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
The mosquito-borne zoonotic flaviviruses West Nile virus (WNV) and Usutu virus (USUV) are endemic in many European countries and emerged in Germany in recent years. Due to the increasing overlap of their distribution areas and their similar epidemiology, coinfections of WNV and USUV are possible. Indeed, coinfections in vertebrate hosts as a rare event have already been reported from some countries including Germany. However, it is largely unknown whether and to what extent coinfections could affect the vector competence of mosquitoes for WNV and USUV. For this purpose, the mosquito species Culex pipiens biotype pipiens, Culex pipiens biotype molestus, and Aedes vexans were orally infected in mono- and simultaneous coinfections with German strains of WNV and USUV. Mosquitoes were incubated for 14 days at 26°C, 85% relative humidity, and a 16 : 8 light-dark photocycle, before they were dissected and forced to salivate. The results showed a decrease in USUV susceptibility in Culex pipiens biotype pipiens, an increase in USUV susceptibility in Aedes vexans, and no obvious interaction between both viruses in Culex pipiens biotype molestus. Vector competence for WNV appeared to be unaffected by a simultaneous occurrence of USUV in all tested mosquito species. Coinfections with both viruses were only found in Culex mosquitoes, and cotransmission of WNV and USUV was observed in Culex pipiens biotype molestus. Overall, our results show that viral interactions between WNV and USUV vary between mosquito species, and that the interaction mainly occurs during infection and replication in the mosquito midgut. The results of this study confirm that to fully understand the interaction between WNV and USUV, studies with various mosquito species are necessary. In addition, we found that even mosquito species with a low susceptibility to both viruses, such as Ae. vexans, can play a role in their transmission in areas with cocirculation.
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13
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Jansen S, Heitmann A, Uusitalo R, Korhonen EM, Lühken R, Kliemke K, Lange U, Helms M, Kirjalainen L, Nykänen R, Gregow H, Pirinen P, Rossini G, Vapalahti O, Schmidt-Chanasit J, Huhtamo E. Vector Competence of Northern European Culex pipiens Biotype pipiens and Culex torrentium to West Nile Virus and Sindbis Virus. Viruses 2023; 15:v15030592. [PMID: 36992301 PMCID: PMC10056470 DOI: 10.3390/v15030592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 02/02/2023] [Accepted: 02/16/2023] [Indexed: 02/24/2023] Open
Abstract
The West Nile Virus (WNV) and Sindbis virus (SINV) are avian-hosted mosquito-borne zoonotic viruses that co-circulate in some geographical areas and share vector species such as Culex pipiens and Culex torrentium. These are widespread in Europe, including northern parts and Finland, where SINV is endemic, but WNV is currently not. As WNV is spreading northwards in Europe, we wanted to assess the experimental vector competence of Finnish Culex pipiens and Culex torrentium mosquitoes to WNV and SINV in different temperature profiles. Both mosquito species were found susceptible to both viruses and got infected via infectious blood meal at a mean temperature of 18 °C. WNV-positive saliva was detected at a mean temperature of 24 °C, whereas SINV-positive saliva was detected already at a mean temperature of 18 °C. Cx. torrentium was found to be a more efficient vector for WNV and SINV over Cx. pipiens. Overall, the results were in line with the previous studies performed with more southern vector populations. The current climate does not seem optimal for WNV circulation in Finland, but temporary summertime transmission could occur in the future if all other essential factors are in place. More field data would be needed for monitoring and understanding the northward spreading of WNV in Europe.
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Affiliation(s)
- Stephanie Jansen
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany
- Faculty of Mathematics, Informatics and Natural Sciences, University of Hamburg, 20146 Hamburg, Germany
| | - Anna Heitmann
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany
| | - Ruut Uusitalo
- Department of Virology, Medicum, University of Helsinki, 00100 Helsinki, Finland
- Department of Veterinary Biosciences, University of Helsinki, 00100 Helsinki, Finland
- Department of Geosciences and Geography, University of Helsinki, 00100 Helsinki, Finland
| | - Essi M. Korhonen
- Department of Virology, Medicum, University of Helsinki, 00100 Helsinki, Finland
- Department of Veterinary Biosciences, University of Helsinki, 00100 Helsinki, Finland
| | - Renke Lühken
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany
| | | | - Unchana Lange
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany
| | - Michelle Helms
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany
| | - Lauri Kirjalainen
- Department of Virology, Medicum, University of Helsinki, 00100 Helsinki, Finland
- Department of Veterinary Biosciences, University of Helsinki, 00100 Helsinki, Finland
| | - Roope Nykänen
- Department of Virology, Medicum, University of Helsinki, 00100 Helsinki, Finland
- Department of Veterinary Biosciences, University of Helsinki, 00100 Helsinki, Finland
| | - Hilppa Gregow
- Finnish Meteorological Institute, 00101 Helsinki, Finland
| | - Pentti Pirinen
- Finnish Meteorological Institute, 00101 Helsinki, Finland
| | - Giada Rossini
- Unit of Microbiology, Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, 40138 Bologna, Italy
| | - Olli Vapalahti
- Department of Virology, Medicum, University of Helsinki, 00100 Helsinki, Finland
- Department of Veterinary Biosciences, University of Helsinki, 00100 Helsinki, Finland
- Virology and Immunology, Diagnostic Center, Helsinki University Hospital (HUSLAB), 00290 Helsinki, Finland
| | - Jonas Schmidt-Chanasit
- Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany
- Faculty of Mathematics, Informatics and Natural Sciences, University of Hamburg, 20146 Hamburg, Germany
| | - Eili Huhtamo
- Department of Virology, Medicum, University of Helsinki, 00100 Helsinki, Finland
- Department of Veterinary Biosciences, University of Helsinki, 00100 Helsinki, Finland
- Correspondence:
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14
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Santos PD, Günther A, Keller M, Homeier-Bachmann T, Groschup MH, Beer M, Höper D, Ziegler U. An advanced sequence clustering and designation workflow reveals the enzootic maintenance of a dominant West Nile virus subclade in Germany. Virus Evol 2023; 9:vead013. [PMID: 37197362 PMCID: PMC10184446 DOI: 10.1093/ve/vead013] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 01/13/2023] [Accepted: 03/16/2023] [Indexed: 05/19/2023] Open
Abstract
West Nile virus (WNV) is the most widespread arthropod-borne (arbo) virus and the primary cause of arboviral encephalitis globally. Members of WNV species genetically diverged and are classified into different hierarchical groups below species rank. However, the demarcation criteria for allocating WNV sequences into these groups remain individual and inconsistent, and the use of names for different levels of the hierarchical levels is unstructured. In order to have an objective and comprehensible grouping of WNV sequences, we developed an advanced grouping workflow using the 'affinity propagation clustering' algorithm and newly included the 'agglomerative hierarchical clustering' algorithm for the allocation of WNV sequences into different groups below species rank. In addition, we propose to use a fixed set of terms for the hierarchical naming of WNV below species level and a clear decimal numbering system to label the determined groups. For validation, we applied the refined workflow to WNV sequences that have been previously grouped into various lineages, clades, and clusters in other studies. Although our workflow regrouped some WNV sequences, overall, it generally corresponds with previous groupings. We employed our novel approach to the sequences from the WNV circulation in Germany 2020, primarily from WNV-infected birds and horses. Besides two newly defined minor (sub)clusters comprising only three sequences each, Subcluster 2.5.3.4.3c was the predominant WNV sequence group detected in Germany from 2018 to 2020. This predominant subcluster was also associated with at least five human WNV infections in 2019-20. In summary, our analyses imply that the genetic diversity of the WNV population in Germany is shaped by enzootic maintenance of the dominant WNV subcluster accompanied by sporadic incursions of other rare clusters and subclusters. Moreover, we show that our refined approach for sequence grouping yields meaningful results. Although we primarily aimed at a more detailed WNV classification, the presented workflow can also be applied to the objective genotyping of other virus species.
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Affiliation(s)
| | | | - Markus Keller
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, 17493, Greifswald-Insel Riems, Germany
| | | | - Martin H Groschup
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, 17493, Greifswald-Insel Riems, Germany
- German Centre for Infection Research, Partner site Hamburg-Lübeck-Borstel-Riems, 17493, Greifswald-Insel Riems, Germany
| | - Martin Beer
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Diagnostic Virology, 17493, Greifswald-Insel Riems, Germany
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15
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Vector Competence of German Aedes punctor (Kirby, 1837) for West Nile Virus Lineages 1 and 2. Viruses 2022; 14:v14122787. [PMID: 36560791 PMCID: PMC9787774 DOI: 10.3390/v14122787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 12/15/2022] Open
Abstract
West Nile virus (WNV) is a zoonotic flavivirus transmitted by mosquitoes as a biological vector. Because of its biting behavior, the widespread snow-melt mosquito Aedes punctor could be a potential bridge vector for WNV to humans and nonhuman mammals. However, little is known on its role in transmission of WNV. The aim of this study was to determine the vector competence of German Ae. punctor for WNV lineages 1 and 2. Field-collected larvae and pupae were reared to adults and offered infectious blood containing either an Italian WNV lineage 1 or a German WNV lineage 2 strain via cotton stick feeding. Engorged females were incubated for 14/15 or 21 days at 18 °C. After incubation; surviving mosquitoes were dissected and forced to salivate. Mosquito bodies with abdomens, thoraces and heads, legs plus wings and saliva samples were investigated for WNV RNA by RT-qPCR. Altogether, 2/70 (2.86%) and 5/85 (5.88%) mosquito bodies were found infected with WNV lineage 1 or 2, respectively. In two mosquitoes, viral RNA was also detected in legs and wings. No saliva sample contained viral RNA. Based on these results, we conclude that Ae. punctor does not play an important role in WNV transmission in Germany.
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16
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Frank C, Schmidt-Chanasit J, Ziegler U, Lachmann R, Preußel K, Offergeld R. West Nile Virus in Germany: An Emerging Infection and Its Relevance for Transfusion Safety. Transfus Med Hemother 2022; 49:192-204. [PMID: 36159956 PMCID: PMC9421668 DOI: 10.1159/000525167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/17/2022] [Indexed: 01/29/2023] Open
Abstract
West Nile virus (WNV) is an arthropod-borne virus (arbovirus). It circulates in an enzootic cycle between ornithophilic mosquitoes as vectors and reservoirs and avian host species for amplification, but humans can be infected as accidental hosts. In most individuals, WNV infection remains silent, while 20% develop mild symptoms of West Nile fever, and only 1% develop neuroinvasive disease (WNND). Human WNV cases have been identified in Southern and Eastern Europe for more than 20 years, but until 2018, Germany was considered to be a non-endemic country. This changed when in the exceptionally warm summer of 2018, conditions for viral replication in mosquitoes were ideal, and the first WNV cases among birds and horses were identified. The widespread domestic Culex mosquitoes are efficient vectors for WNV. Autochthonous mosquito-borne WNV infections in humans were reported in all following years, indicating a continuous circulation in the affected areas of Central-East Germany. So far, no clear expansion of the affected areas is discernible but may develop. WNV is a transfusion-transmissible-infection, and donor deferral or testing of donations after a stay in an affected area are effective means to ensure transfusion safety. WNV transmissions via blood products often result in WNND due to the predisposing underlying medical conditions of transfusion recipients. From 2020 onwards, roughly 80% of all blood establishments in Germany tested their donations for WNV using nucleic acid amplification techniques in the transmission season. Altogether, 19 confirmed WNV infections were identified from 2020-2021. As long as effective and affordable pathogen reduction is not available for all blood components, WNV testing or donor deferral will be essential. In order to timely identify affected areas, combined results of human and veterinary surveillance are needed. Partnerships between public health experts, transfusion medicine specialists, veterinarians, and entomologists should be strengthened to ensure a One Health approach.
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Affiliation(s)
- Christina Frank
- Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany
| | - Jonas Schmidt-Chanasit
- Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Haemorrhagic Fever Reference and Research, Hamburg, Germany
| | - Ute Ziegler
- Friedrich Loeffler Institute, Institute of Novel and Emerging Infectious Diseases, Greifswald-Insel Riems, Greifswald, Germany
| | - Raskit Lachmann
- Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany
| | - Karina Preußel
- Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany
| | - Ruth Offergeld
- Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany
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17
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Pallari CT, Christodoulou V, Koliou M, Kirschel ANG. First detection of WNV RNA presence in field-collected mosquitoes in Cyprus. Acta Trop 2022; 231:106470. [PMID: 35430264 DOI: 10.1016/j.actatropica.2022.106470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 01/01/2023]
Abstract
West Nile virus (WNV) infections have increased over recent years to the extent that WNV has become one of the most widespread arboviruses in the world, with potential consequences for both human and animal health. While much is known about WNV and the vectors that transmit it from their primary hosts across continental Europe, little is known about the epidemiology of the disease on the island of Cyprus. In this study, the aim was to investigate the prevalence of WNV infection in potential mosquito vectors for the first time in the Republic of Cyprus, using WNV surveillance of mosquitoes. Mosquitoes were collected in 2019, during which an outbreak in humans had occurred, and sampled mosquitoes were then examined for WNV infection by testing them for the presence of WNV RNA. Of 126 mosquito pools tested, one pool, containing Culex pipiens mosquitoes sampled from the Nicosia district, was found to be positive for the presence of WNV RNA. The positive pool found in this study represents the first demonstration of WNV in mosquitoes in Cyprus and confirms that human cases in Cyprus are likely the result of transmission via local Culex mosquitoes.
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Affiliation(s)
- Chryso Th Pallari
- Department of Biological Sciences, University of Cyprus, PO Box 20537, Nicosia, 1678, Cyprus
| | | | - Maria Koliou
- Medical School, University of Cyprus, Siakoleio Center of Clinical Medicine, 2029 Aglantzia PO Box 20537, 1678, Nicosia, Cyprus
| | - Alexander N G Kirschel
- Department of Biological Sciences, University of Cyprus, PO Box 20537, Nicosia, 1678, Cyprus.
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18
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Reemtsma H, Holicki CM, Fast C, Bergmann F, Eiden M, Groschup MH, Ziegler U. Pathogenesis of West Nile Virus Lineage 2 in Domestic Geese after Experimental Infection. Viruses 2022; 14:v14061319. [PMID: 35746790 PMCID: PMC9230372 DOI: 10.3390/v14061319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 06/03/2022] [Accepted: 06/14/2022] [Indexed: 11/18/2022] Open
Abstract
West Nile virus (WNV) is an emerging infectious pathogen circulating between mosquitoes and birds but also infecting mammals. WNV has become autochthonous in Germany, causing striking mortality rates in avifauna and occasional diseases in humans and horses. We therefore wanted to assess the possible role of free-ranging poultry in the WNV transmission cycle and infected 15 goslings with WNV lineage 2 (German isolate). The geese were monitored daily and sampled regularly to determine viremia, viral shedding, and antibody development by molecular and serological methods. Geese were euthanized at various time points post-infection (pi). All infected geese developed variable degrees of viremia from day 1 to day 10 (maximum) and actively shed virus from days 2 to 7 post-infection. Depending on the time of death, the WN viral genome was detected in all examined tissue samples in at least one individual by RT-qPCR and viable virus was even re-isolated, except for in the liver. Pathomorphological lesions as well as immunohistochemically detectable viral antigens were found mainly in the brain. Furthermore, all of the geese seroconverted 6 days pi at the latest. In conclusion, geese are presumably not functioning as important amplifying hosts but are suitable sentinel animals for WNV surveillance.
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19
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Ganzenberg S, Sieg M, Ziegler U, Pfeffer M, Vahlenkamp TW, Hörügel U, Groschup MH, Lohmann KL. Seroprevalence and Risk Factors for Equine West Nile Virus Infections in Eastern Germany, 2020. Viruses 2022; 14:v14061191. [PMID: 35746662 PMCID: PMC9229339 DOI: 10.3390/v14061191] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/23/2022] [Accepted: 05/25/2022] [Indexed: 11/16/2022] Open
Abstract
West Nile virus (WNV) infections were first detected in Germany in 2018, but information about WNV seroprevalence in horses is limited. The study’s overall goal was to gather information that would help veterinarians, horse owners, and veterinary-, and public health- authorities understand the spread of WNV in Germany and direct protective measures. For this purpose, WNV seroprevalence was determined in counties with and without previously registered WNV infections in horses, and risk factors for seropositivity were estimated. The cohort consisted of privately owned horses from nine counties in Eastern Germany. A total of 940 serum samples was tested by competitive panflavivirus ELISA (cELISA), and reactive samples were further tested by WNV IgM capture ELISA and confirmed by virus neutralization test (VNT). Information about potential risk factors was recorded by questionnaire and analyzed by logistic regression. A total of 106 serum samples showed antibodies against flaviviruses by cELISA, of which six tested positive for WNV IgM. The VNT verified a WNV infection for 54 samples (50.9%), while 35 sera neutralized tick-borne encephalitis virus (33.0%), and eight sera neutralized Usutu virus (7.5%). Hence, seroprevalence for WNV infection was 5.8% on average and was significantly higher in counties with previously registered infections (p = 0.005). The risk factor analysis showed breed type (pony), housing in counties with previously registered infections, housing type (24 h turn-out), and presence of outdoor shelter as the main significant risk factors for seropositivity. In conclusion, we estimated the extent of WNV infection in the resident horse population in Eastern Germany and showed that seroprevalence was higher in counties with previously registered equine WNV infections.
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Affiliation(s)
- Stefanie Ganzenberg
- Department for Horses, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany;
| | - Michael Sieg
- Institute of Virology, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany; (M.S.); (T.W.V.)
| | - Ute Ziegler
- Friedrich-Loeffler Institut (FLI), Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, 17493 Greifswald-Insel Riems, Germany; (U.Z.); (M.H.G.)
| | - Martin Pfeffer
- Institute of Animal Hygiene and Veterinary Public Health, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany;
| | - Thomas W. Vahlenkamp
- Institute of Virology, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany; (M.S.); (T.W.V.)
| | - Uwe Hörügel
- Animal Diseases Fund Saxony, Pferdegesundheitsdienst, 01099 Dresden, Germany;
| | - Martin H. Groschup
- Friedrich-Loeffler Institut (FLI), Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, 17493 Greifswald-Insel Riems, Germany; (U.Z.); (M.H.G.)
| | - Katharina L. Lohmann
- Department for Horses, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany;
- Correspondence: ; Tel.: +49-341-97-38224
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20
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Spread of West Nile Virus and Usutu Virus in the German Bird Population, 2019–2020. Microorganisms 2022; 10:microorganisms10040807. [PMID: 35456857 PMCID: PMC9030481 DOI: 10.3390/microorganisms10040807] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 04/04/2022] [Accepted: 04/09/2022] [Indexed: 12/21/2022] Open
Abstract
West Nile virus (WNV) and Usutu virus (USUV) are important flaviviruses circulating in Germany. While USUV was first reported more than 10 years ago, WNV has only reached the country in 2018. Wild birds are important amplifying hosts for both viruses. Therefore, we have been monitoring the bird population in different regions of Germany by a previously established network for many years. This report summarizes the results of molecular and/or serological methods of 2345 blood samples from birds of 22 different orders and over 2900 bird carcasses from 2019 and 2020. USUV RNA circulation was found in different regions of Germany, with emphasis on USUV lineages Europe 3 and Africa 3. Increased evidence of USUV lineage Europe 2 was detected in eastern Germany. WNV RNA was found only in birds from the eastern part of the country. The seroprevalence for USUV was between 3.11% and 7.20% in all three regions investigated, whereas the WNV seroprevalence spanned from 14.77% to 16.15% in eastern Germany, with a noticeable tendency for a westward and southward expansion in both years. Thus, wild bird monitoring for WNV and USUV can serve as an early warning system for a human exposure risk.
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21
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Schneider J, Bachmann F, Choi M, Kurvits L, Luisa Schmidt M, Bergfeld L, Meier I, Zuchowski M, Werber D, Hofmann J, Ruprecht K, Eckardt KU, Carleton Jones T, Drosten C, Max Corman V. Autochthonous West Nile virus infection in Germany: Increasing numbers and a rare encephalitis case in a kidney transplant recipient. Transbound Emerg Dis 2022; 69:221-226. [PMID: 34850584 PMCID: PMC8969181 DOI: 10.1111/tbed.14406] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/07/2021] [Accepted: 11/17/2021] [Indexed: 12/15/2022]
Abstract
West Nile Virus (WNV) infections are increasingly detected in birds and horses in central Europe, with the first mosquito-borne autochthonous human infection detected in Germany in 2019. Human infections are typically asymptomatic, with occasional severe neurological disease. Because of a low number of cases in central Europe, awareness regarding potential cases is low and WNV diagnostic testing is not routine. We tested cerebrospinal fluid (CSF) samples from unsolved encephalitis and meningitis cases from Berlin from 2019 to 2020, and describe a WNV-encephalitis case in a 33-year-old kidney transplant recipient. The infectious course was resolved by serology, RT-PCR and sequencing of stored samples. Phylogenetic sequence analysis revealed a close relationship of the patient's WNV strain to German sequences from 2019 and 2020. A lack of travel history and patient self-isolation during the SARS-CoV-2 pandemic suggest the infection was acquired in the patient's home or garden. Serological tests of four people sharing the living space were negative. Retrospective RT-PCR and WNV-IgM testing of 671 CSF samples from unsolved encephalitis and meningitis cases from Berlin detected no additional infections. The recent increase of WNV cases illustrates the importance of considering WNV in cases of meningoencephalitis, especially in immunocompromised patients, as described here. Proper education and communication and a revised diagnostic strategy will help to raise awareness and to detect future WNV infections.
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Affiliation(s)
- Julia Schneider
- Institute of Virology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany,German Centre for Infection Research (DZIF), partner site Charité, Berlin, Germany
| | - Friederike Bachmann
- Department of Nephrology and Medical Intensive Care, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Mira Choi
- Department of Nephrology and Medical Intensive Care, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Lille Kurvits
- Department of Neurology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Marie Luisa Schmidt
- Institute of Virology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Leon Bergfeld
- Institute of Virology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Iris Meier
- State Office for Health and Social Affairs, Berlin, Germany
| | | | - Dirk Werber
- State Office for Health and Social Affairs, Berlin, Germany
| | - Jörg Hofmann
- Labor Berlin-Charité Vivantes GmbH, Berlin, Germany
| | - Klemens Ruprecht
- Department of Neurology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Kai-Uwe Eckardt
- Department of Nephrology and Medical Intensive Care, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Terry Carleton Jones
- Institute of Virology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany,German Centre for Infection Research (DZIF), partner site Charité, Berlin, Germany,Centre for Pathogen Evolution, Department of Zoology, University of Cambridge, Cambridge, U.K
| | - Christian Drosten
- Institute of Virology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany,German Centre for Infection Research (DZIF), partner site Charité, Berlin, Germany
| | - Victor Max Corman
- Institute of Virology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany,German Centre for Infection Research (DZIF), partner site Charité, Berlin, Germany
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22
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Kerkow A, Wieland R, Gethmann JM, Hölker F, Lentz HH. Linking a compartment model for West Nile virus with a flight simulator for vector mosquitoes. Ecol Modell 2022. [DOI: 10.1016/j.ecolmodel.2021.109840] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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23
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Seroepidemiological Survey of West Nile Virus Infections in Horses from Berlin/Brandenburg and North Rhine-Westphalia, Germany. Viruses 2022; 14:v14020243. [PMID: 35215837 PMCID: PMC8877243 DOI: 10.3390/v14020243] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 01/14/2022] [Accepted: 01/21/2022] [Indexed: 02/01/2023] Open
Abstract
Following the introduction of the West Nile virus (WNV) into eastern Germany in 2018, increasing infections have been diagnosed in birds, equines, and humans over time, while the spread of WNV into western Germany remained unclear. We screened 437 equine sera from 2018 to 2020, excluding vaccinated horses, collected from convenience sampled patients in the eastern and western parts of Germany, for WNV-specific antibodies (ELISAs followed by virus/specific neutralization tests) and genomes (RT-qPCRs). Clinical presentations, final diagnoses, and demographic data were also recorded. In the eastern part, a total of eight horses were found WNV seropositive in 2019 (seroprevalence of 8.16%) and 27 in 2020 (13.77%). There were also two clinically unsuspected horses with WNV-specific antibodies in the western part from 2020 (2.63%), albeit travel history-related infections could not be excluded. None of the horse sera contained WNV-specific genomes. Eight horses in eastern Germany carried WNV-IgM antibodies, but only four of these showed typical clinical signs. These results underline the difficulty of detecting a WNV infection in a horse solely based on clinical signs. Thus, WNV circulation is established in the horse population in eastern Germany, but not yet in the western part.
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24
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First Evidence of West Nile Virus Overwintering in Mosquitoes in Germany. Viruses 2021; 13:v13122463. [PMID: 34960732 PMCID: PMC8703620 DOI: 10.3390/v13122463] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/01/2021] [Accepted: 12/04/2021] [Indexed: 01/31/2023] Open
Abstract
Mosquitoes collected from mid-December 2020 to early March 2021 from hibernacula in northeastern Germany, a region of West Nile virus (WNV) activity since 2018, were examined for WNV-RNA. Among the 6101 mosquitoes tested in 722 pools of up to 12 specimens, one pool of 10 Culex pipiens complex mosquitoes collected in early March 2021 in the cellar of a medieval castle in Rosslau, federal state of Saxony-Anhalt, tested positive. Subsequent mosquito DNA analysis produced Culex pipiens biotype pipiens. The pool homogenate remaining after nucleic acid extraction failed to grow the virus on Vero and C6/36 cells. Sequencing of the viral NS2B-NS3 coding region, however, demonstrated high homology with virus strains previously collected in Germany, e.g., from humans, birds, and mosquitoes, which have been designated the East German WNV clade. The finding confirms the expectation that WNV can overwinter in mosquitoes in Germany, facilitating an early start to the natural transmission season in the subsequent year. On the other hand, the calculated low infection prevalence of 0.016–0.20%, depending on whether one or twelve of the mosquitoes in the positive pool was/were infected, indicates a slow epidemic progress and mirrors the still-hypoendemic situation in Germany. In any case, local overwintering of the virus in mosquitoes suggests its long-term persistence and an enduring public health issue.
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25
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Hohmeister N, Werner D, Kampen H. The invasive Korean bush mosquito Aedes koreicus (Diptera: Culicidae) in Germany as of 2020. Parasit Vectors 2021; 14:575. [PMID: 34772448 PMCID: PMC8588644 DOI: 10.1186/s13071-021-05077-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 10/19/2021] [Indexed: 11/22/2022] Open
Abstract
Background The Korean bush mosquito Aedes koreicus was recently reported to have established a population in western Germany (Wiesbaden) in 2016. The species is difficult to distinguish morphologically from its close relative, the invasive Japanese bush mosquito Ae. japonicus, which is already widely distributed in many parts of Germany, including the area colonised by Ae. koreicus. Genetic confirmation of morphologically identified “Ae. japonicus” collection material, however, had only been done exceptionally before the German Ae. koreicus population became known. Methods Dried archived “Ae. japonicus” specimens both from the municipality of Wiesbaden and from deliberately and randomly selected distribution sites all over Germany were re-examined morphologically and genetically for admixture by Ae. koreicus. Moreover, cemeteries in the greater Wiesbaden area were sampled in 2019 and 2020 to check for Ae. koreicus spread. Korean and Japanese bush mosquitoes submitted to the German citizen science mosquito monitoring scheme “Mueckenatlas” in 2019 and 2020 were also subjected to particularly thorough species identification. The ND4 DNA sequences generated in this study in the context of species identification were phylogenetically compared to respective GenBank entries of Ae. koreicus. As a by-product, several genetic markers were evaluated for their suitability to identify Ae. koreicus. Results Aedes koreicus specimens could be identified in mosquito collection material and submissions from Wiesbaden from 2015 onwards, suggesting establishment to have happened in the same year as Ae. japonicus establishment. Detections of Ae. koreicus from 2019 and 2020 in Wiesbaden indicate a negligible enlargement of the populated area as described for 2018. Two Ae. koreicus specimens were also submitted from the city of Munich, southern Germany, in 2019 but further specimens could not be identified during immediate local inspections. Comparison of ND4 sequences generated in this and other studies demonstrate a high degree of homology, suggesting that this DNA region is not informative enough for clarification of origins and relationships of Ae. koreicus populations. For genetic identification of Ae. koreicus, PCR primers used for classical CO1 barcoding were found to lead to mismatches and produce no or incorrect amplicons. Alternative CO1 primers or a validated ND4 marker should be used instead. Conclusions Aedes koreicus is probably introduced into Germany every now and then but rarely succeeds in becoming established. As with most European populations, the German population is characterised by a limited expansion tendency. Since Ae. koreicus is a potential vector, however, Asian bush mosquitoes found at new places should be examined quite carefully and known distribution areas of Ae. japonicus regularly checked for the presence of Ae. koreicus. Graphical Abstract ![]()
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Affiliation(s)
- Nicolas Hohmeister
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Greifswald, Germany
| | - Doreen Werner
- Leibniz-Centre for Agricultural Landscape Research, Muencheberg, Germany
| | - Helge Kampen
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Greifswald, Germany.
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26
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Fynmore N, Lühken R, Maisch H, Risch T, Merz S, Kliemke K, Ziegler U, Schmidt-Chanasit J, Becker N. Rapid assessment of West Nile virus circulation in a German zoo based on honey-baited FTA cards in combination with box gravid traps. Parasit Vectors 2021; 14:449. [PMID: 34488835 PMCID: PMC8419893 DOI: 10.1186/s13071-021-04951-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/12/2021] [Indexed: 11/30/2022] Open
Abstract
Background For over a decade, monitoring of West Nile virus (WNV) in Germany has consisted of a bird monitoring programme as well as a mosquito-based surveillance programme employing CO2-baited encephalitis vector surveillance (EVS) traps for mass trapping and screening of mosquitoes. In contrast to the EVS traps, the Reiter/Cummings type box gravid trap collects gravid female mosquitoes, which have already taken a blood meal, increasing the likelihood of being infected with pathogens. The traps can be equipped with a honey-baited Flinders Technology Associates® (FTA) card to encourage sugar feeding by the trapped mosquitoes. FTA cards contain nucleic acid preserving substances, which prevent the degradation of viral RNA in the expectorated mosquito saliva and allows for testing the card for flavivirus RNA. This study aimed to assess the suitability of the method for WNV surveillance in Germany as an alternative to previous methods, which are expensive, time-consuming, and predominantly target host-seeking populations less likely to be infected with WNV. Methods In the Thüringer Zoopark Erfurt, snowy owls (Nyctea scandiaca) and greater flamingos (Phoenicopterus roseus) died of WNV infections in July and August 2020. In response, five Reiter/Cummings type box gravid traps were positioned during the daytime on the 10th, 13th, and 16th of September in five different locations. The FTA cards and mosquitoes in the chamber were collected, kept in a cool chain, and further processed for virus detection using a modified generic flavivirus reverse transcription PCR. Results A total of 15 trappings during September collected a total of 259 female mosquitoes, 97% of which were Culex pipiens sensu lato, as well as 14 honey-baited FTA cards. Eight mosquitoes tested PCR-positive for WNV. Four FTA cards tested PCR-positive for mosquito-borne flaviviruses, two of which were confirmed as WNV, and the remaining two confirmed as Usutu virus. Conclusion The suitability of the FTA cards in preserving viral RNA in the field and rapid turnaround time from collection to result is combined with a simple, cost-effective, and highly specific trapping method to create an arbovirus surveillance system, which circumvents many of the difficulties of previous surveillance programmes that required the analysis of mosquitoes in the laboratory. Graphical Abstract ![]()
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Affiliation(s)
- Noelle Fynmore
- Institute of Dipterology (IfD), Georg-Peter-Süß-Str. 3, 67346, Speyer, Germany.,The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG, UK
| | - Renke Lühken
- Department of Arbovirology, Bernhard-Nocht-Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, 20359, Hamburg, Germany
| | - Heike Maisch
- Thüringer Zoopark Erfurt, Am Zoopark 1, 99087, Erfurt, Germany
| | - Tina Risch
- Thüringer Zoopark Erfurt, Am Zoopark 1, 99087, Erfurt, Germany
| | - Sabine Merz
- Thüringer Zoopark Erfurt, Am Zoopark 1, 99087, Erfurt, Germany
| | - Konstantin Kliemke
- Department of Arbovirology, Bernhard-Nocht-Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, 20359, Hamburg, Germany
| | - Ute Ziegler
- Friedrich-Loeffler Institut, Institute of Novel and Emerging Infectious Diseases, Südufer 10, 17493, Greifswald-Insel Riems, Germany
| | - Jonas Schmidt-Chanasit
- Department of Arbovirology, Bernhard-Nocht-Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, 20359, Hamburg, Germany.,Faculty of Mathematics, Informatics and Natural Sciences, Universität Hamburg, Hamburg, Germany
| | - Norbert Becker
- Institute of Dipterology (IfD), Georg-Peter-Süß-Str. 3, 67346, Speyer, Germany. .,Faculty of Biosciences, Heidelberg University, Im Neuenheimer Feld 230, 69120, Heidelberg, Germany.
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27
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Trachsel DS, Drozdzewska K, Bergmann F, Ziegler U, Gehlen H. [Confirmed case of a West Nile virus infection in a horse with minimal neurological signs and a favorable clinical outcome]. Tierarztl Prax Ausg G Grosstiere Nutztiere 2021; 49:281-286. [PMID: 34425618 DOI: 10.1055/a-1519-4547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
West Nile virus (WNV) is a mosquito-borne viral pathogen of global importance and is considered to be the most widespread flavivirus. In Germany, first infections with WNV were detected in 2018 and it is expected for these to become more frequent in consequence to warmer winters followed by a rainy/humid springtime. WNV is maintained in an enzootic cycle between ornithophilic mosquitoes and certain wild bird species. Humans and horses are so-called "dead-end hosts" of a WNV infection. They frequently do not fall ill, however occasionally develop overt infections ranging from mild febrile symptoms (so-called "West Nile fever") up to severe encephalitis with fatal outcome. Therefore, it is important to recognize the clinical signs and to be able to distinguish a WNV infection from other possible differential diagnoses. The presented case report highlights rather uncommon clinical signs of a WNV infection such as non-specific fever, anorexia, or colic-like symptoms. In addition, possible differential diagnoses as well as the treatment are discussed. The time course of neutralizing antibodies following natural infection is reported, showing high levels of antibodies 7 months following the infection. Finally, antibody measurements demonstrated a very good immunologic response following a single WNV vaccination.
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Affiliation(s)
- Dagmar S Trachsel
- Klinik für Pferde, allgemeine Chirurgie und Radiologie, Freie Universität Berlin
| | - Karolina Drozdzewska
- Klinik für Pferde, allgemeine Chirurgie und Radiologie, Freie Universität Berlin
| | - Felicitas Bergmann
- Friedrich-Loeffler-Institut, Institut für neue und neuartige Tierseuchenerreger, Greifswald-Insel Riems
| | - Ute Ziegler
- Friedrich-Loeffler-Institut, Institut für neue und neuartige Tierseuchenerreger, Greifswald-Insel Riems
| | - Heidrun Gehlen
- Klinik für Pferde, allgemeine Chirurgie und Radiologie, Freie Universität Berlin
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29
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Alzuheir I, Fayyad A, Jalboush N, Abdallah R, Abutarbush S, Gharaibeh M, Bdarneh M, Khraim N, Helal MA, Helal BA. Seroprevalence and risk factors of West Nile virus infection in veterinarians and horses in Northern Palestine. Vet World 2021; 14:1241-1246. [PMID: 34220126 PMCID: PMC8243691 DOI: 10.14202/vetworld.2021.1241-1246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 04/06/2021] [Indexed: 11/16/2022] Open
Abstract
Background and Aim West Nile fever (WNF) is a neurotropic, mosquito-borne disease affecting humans and domesticated animals, caused by a member of the genus Flavivirus. Over the last decades, this virus has been responsible for several cases of illness in humans and animals. The current epidemiological status of WNF in horses is insufficient, and in veterinarians, as an occupational hazard is unknown. This study aimed to investigate and determine the seroprevalence and risk factors for WNF in veterinarians and horses in Palestine. Materials and Methods In this study, serum samples from 100 veterinarians and 87 horses were collected between August 2020 and September 2020 from different cities of Northern Palestine. West Nile virus (WNV) antibodies were detected using an enzyme-linked immunosorbent assay. Results Our results showed that 60.9% of the horse serum samples were positive in all investigated cities. In horses, location is a risk factor for the seropositivity for WNF, whereas age, sex, breed, and intended use of the horses, were not associated with increased WNF seropositivity. In veterinarians, 23.0% of the serum samples were positive. Positive samples were detected in all locations, age groups, experience length, and work sectors. However, the seropositivity for WNF was not influenced by these variables. Conclusion The results revealed that WNV circulates in most regions of Palestine. Our results will help determine the risk of infection in animals and humans and control WNV transmission. Surveillance studies on humans, vectors, and animals are needed to better define endemic areas.
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Affiliation(s)
- Ibrahim Alzuheir
- Department of Veterinary Medicine, An-Najah National University, P.O. Box 7 Nablus, Palestine
| | - Adnan Fayyad
- Department of Veterinary Medicine, An-Najah National University, P.O. Box 7 Nablus, Palestine
| | - Nasr Jalboush
- Department of Veterinary Medicine, An-Najah National University, P.O. Box 7 Nablus, Palestine
| | | | - Sameeh Abutarbush
- Department of Clinical Veterinary Medical Sciences, Faculty of Veterinary Medicine, Jordan University of Science and Technology, P.O. Box 3030 Irbid, 22110 Jordan
| | - Mohammad Gharaibeh
- Department of Basic Veterinary Medical Science, Faculty of Veterinary Medicine, Jordan University of Science and Technology, P. O. Box 3030 Irbid, 22110, Jordan
| | - Majd Bdarneh
- Department of Clinical Veterinary Medical Sciences, Faculty of Veterinary Medicine, Jordan University of Science and Technology, P.O. Box 3030 Irbid, 22110 Jordan
| | - Nimer Khraim
- Department of Veterinary Medicine, An-Najah National University, P.O. Box 7 Nablus, Palestine
| | - Mohammad Abu Helal
- Department of Public Health Sciences, Faculty of Graduate Studies, An-Najah National University, P.O. Box 7 Nablus, Palestine
| | - Belal Abu Helal
- Department of Veterinary Medicine, An-Najah National University, P.O. Box 7 Nablus, Palestine
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30
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Pietsch C, Michalski D, Münch J, Petros S, Bergs S, Trawinski H, Lübbert C, Liebert UG. Autochthonous West Nile virus infection outbreak in humans, Leipzig, Germany, August to September 2020. ACTA ACUST UNITED AC 2021; 25. [PMID: 33213686 PMCID: PMC7678033 DOI: 10.2807/1560-7917.es.2020.25.46.2001786] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Following a distinct summer heat wave, nine autochthonous cases of West Nile fever and West Nile neuroinvasive disease, including one fatality, were observed in Leipzig, Germany, in August and September 2020. Phylogenetic analysis demonstrated close relationships in viruses from humans, animals and mosquitos in eastern Germany, obtained during the preceding 2 years. The described large cluster of autochthonous West Nile virus infections in Germany indicates endemic seasonal circulation of lineage 2 viruses in the area.
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Affiliation(s)
- Corinna Pietsch
- Institute of Virology, Leipzig University Hospital, Leipzig, Germany; Interdisciplinary Centre for Infectious Diseases, Leipzig University Hospital, Leipzig, Germany
| | - Dominik Michalski
- Department of Neurology, Leipzig University Hospital, Leipzig, Germany
| | - Johannes Münch
- Division of Nephrology, Department of Endocrinology, Nephrology and Rheumatology, Leipzig University Hospital, Leipzig, Germany
| | - Sirak Petros
- Medical ICU, Leipzig University Hospital, Leipzig, Germany
| | - Sandra Bergs
- Institute of Virology, Leipzig University Hospital, Leipzig, Germany; Interdisciplinary Centre for Infectious Diseases, Leipzig University Hospital, Leipzig, Germany
| | - Henning Trawinski
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine II, Leipzig University Hospital, Leipzig, Germany; Interdisciplinary Centre for Infectious Diseases, Leipzig University Hospital, Leipzig, Germany
| | - Christoph Lübbert
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine II, Leipzig University Hospital, Leipzig, Germany; Interdisciplinary Centre for Infectious Diseases, Leipzig University Hospital, Leipzig, Germany
| | - Uwe G Liebert
- Institute of Virology, Leipzig University Hospital, Leipzig, Germany; Interdisciplinary Centre for Infectious Diseases, Leipzig University Hospital, Leipzig, Germany
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Früh L, Kampen H, Koban MB, Pernat N, Schaub GA, Werner D. Oviposition of Aedes japonicus japonicus (Diptera: Culicidae) and associated native species in relation to season, temperature and land use in western Germany. Parasit Vectors 2020; 13:623. [PMID: 33334377 PMCID: PMC7744736 DOI: 10.1186/s13071-020-04461-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 11/05/2020] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Aedes japonicus japonicus, first detected in Europe in 2000 and considered established in Germany 10 years later, is of medical importance due to its opportunistic biting behaviour and its potential to transmit pathogenic viruses. Its seasonal phenology, temperature and land use preference related to oviposition in newly colonised regions remain unclear, especially in the context of co-occurring native mosquito species. METHODS Focussing on regions in Germany known to be infested by Ae. japonicus japonicus, we installed ovitraps in different landscapes and their transition zones and recorded the oviposition activity of mosquitoes in relation to season, temperature and land use (arable land, forest, settlement) in two field seasons (May-August 2017, April-November 2018). RESULTS Ae. japonicus japonicus eggs and larvae were encountered in 2017 from June to August and in 2018 from May to November, with a markedly high abundance from June to September in rural transition zones between forest and settlement, limited to water temperatures below 30 °C. Of the three native mosquito taxa using the ovitraps, the most frequent was Culex pipiens s.l., whose offspring was found in high numbers from June to August at water temperatures of up to 35 °C. The third recorded species, Anopheles plumbeus, rarely occurred in ovitraps positioned in settlements and on arable land, but was often associated with Ae. japonicus japonicus. The least frequent species, Aedes geniculatus, was mostly found in ovitraps located in the forest. CONCLUSIONS The transition zone between forest and settlement was demonstrated to be the preferred oviposition habitat of Ae. japonicus japonicus, where it was also the most frequent container-inhabiting mosquito species in this study. Compared to native taxa, Ae. japonicus japonicus showed an extended seasonal activity period, presumably due to tolerance of colder water temperatures. Higher water temperatures and arable land represent distribution barriers to this species. The frequently co-occurring native species An. plumbeus might be useful as an indicator for potentially suitable oviposition habitats of Ae. japonicus japonicus in hitherto uncolonised regions. The results contribute to a better understanding of mosquito ecology and provide a basis for more targeted monitoring, distribution modelling and risk management of mosquitoes.
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Affiliation(s)
- Linus Früh
- Leibniz Centre for Agricultural Landscape Research, Eberswalder Straße 84, 15374 Müncheberg, Germany
- Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany
| | - Helge Kampen
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, Insel Riems, 17493 Greifswald, Germany
| | - Marcel B. Koban
- Leibniz Centre for Agricultural Landscape Research, Eberswalder Straße 84, 15374 Müncheberg, Germany
- Universität Hohenheim, Garbenstraße 30, 70593 Stuttgart, Germany
| | - Nadja Pernat
- Leibniz Centre for Agricultural Landscape Research, Eberswalder Straße 84, 15374 Müncheberg, Germany
- Freie Universität Berlin, Königin-Luise-Straße 1-3, 14195 Berlin, Germany
| | - Günter A. Schaub
- Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany
| | - Doreen Werner
- Leibniz Centre for Agricultural Landscape Research, Eberswalder Straße 84, 15374 Müncheberg, Germany
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Pathogenicity of West Nile Virus Lineage 1 to German Poultry. Vaccines (Basel) 2020; 8:vaccines8030507. [PMID: 32899581 PMCID: PMC7563189 DOI: 10.3390/vaccines8030507] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 08/27/2020] [Accepted: 09/02/2020] [Indexed: 12/17/2022] Open
Abstract
West Nile virus (WNV) is a mosquito-borne virus that originates from Africa and at present causes neurological disease in birds, horses, and humans all around the globe. As West Nile fever is an important zoonosis, the role of free-ranging domestic poultry as a source of infection for humans should be evaluated. This study examined the pathogenicity of an Italian WNV lineage 1 strain for domestic poultry (chickens, ducks, and geese) held in Germany. All three species were subcutaneously injected with WNV, and the most susceptible species was also inoculated via mosquito bite. All species developed various degrees of viremia, viral shedding (oropharyngeal and cloacal), virus accumulation, and pathomorphological lesions. Geese were most susceptible, displaying the highest viremia levels. The tested waterfowl, geese, and especially ducks proved to be ideal sentinel species for WNV due to their high antibody levels and relatively low blood viral loads. None of the three poultry species can function as a reservoir/amplifying host for WNV, as their viremia levels most likely do not suffice to infect feeding mosquitoes. Due to the recent appearance of WNV in Germany, future pathogenicity studies should also include local virus strains.
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Feyer S, Bartenschlager F, Bertram CA, Ziegler U, Fast C, Klopfleisch R, Müller K. Clinical, pathological and virological aspects of fatal West Nile virus infections in ten free-ranging goshawks (Accipiter gentilis) in Germany. Transbound Emerg Dis 2020; 68:907-919. [PMID: 32743905 DOI: 10.1111/tbed.13759] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 07/09/2020] [Accepted: 07/26/2020] [Indexed: 01/21/2023]
Abstract
West Nile virus (WNV), a zoonotic arbovirus, is a new epizootic disease in Germany and caused increasing avian and equine mortality since its first detection in 2018. The northern goshawk (Accipiter gentilis) is highly susceptible to fatal WNV disease and thus is considered as an indicator species for WNV emergence in European countries. Therefore, information regarding clinical presentation and pathological findings is important for identifying suspect cases and initiating further virological diagnostics. Between July and September 2019, ten free-ranging goshawks were admitted to the Small Animal Clinic of the Freie Universität Berlin with later confirmed WNV infection. Clinical, pathological and virological findings are summarized in this report. All birds were presented obtunded and in poor to cachectic body condition. Most of the birds were juveniles (8/10) and females (9/10). Neurologic abnormalities were observed in all birds and included stupor (3/10), seizures (3/10), head tremor (2/10), head tilt (2/10), ataxia (2/10) and monoplegia (2/10). Concurrent diseases like aerosacculitis/pneumonia (7/10), clinical infections with Eucoleus spp. and Trichomonas spp. (3/10), trauma-related injuries (3/10) and myiasis (2/10) were found. Blood analysis results were unspecific considering concurrent diseases. Median time of survival was two days. The most common pathological findings were meningoencephalitis (9/10), myocarditis (8/10), iridocyclitis (8/8) and myositis (7/10). WNV infection was diagnosed by real-time quantitative reverse transcription polymerase chain reaction and confirmed by serology and immunohistochemistry.
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Affiliation(s)
- Sina Feyer
- Small Animal Clinic, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Florian Bartenschlager
- Institute of Veterinary Pathology, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Christof A Bertram
- Institute of Veterinary Pathology, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Ute Ziegler
- Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Greifswald-Insel Riems, Germany
| | - Christine Fast
- Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Greifswald-Insel Riems, Germany
| | - Robert Klopfleisch
- Institute of Veterinary Pathology, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Kerstin Müller
- Small Animal Clinic, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
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Werner D, Kowalczyk S, Kampen H. Nine years of mosquito monitoring in Germany, 2011-2019, with an updated inventory of German culicid species. Parasitol Res 2020; 119:2765-2774. [PMID: 32671542 PMCID: PMC7431392 DOI: 10.1007/s00436-020-06775-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 06/15/2020] [Indexed: 12/18/2022]
Abstract
Before the background of increasingly frequent outbreaks and cases of mosquito-borne diseases in various European countries, Germany recently realised the necessity of updating decade-old data on the occurrence and spatiotemporal distribution of culicid species. Starting in 2011, a mosquito monitoring programme was therefore launched with adult and immature mosquito stages being collected at numerous sites all over Germany both actively by trapping, netting, aspirating and dipping, and passively by the citizen science project 'Mueckenatlas'. Until the end of 2019, about 516,000 mosquito specimens were analysed, with 52 (probably 53) species belonging to seven genera found, including several species not reported for decades due to being extremely rare (Aedes refiki, Anopheles algeriensis, Culex martinii) or local (Culiseta alaskaensis, Cs. glaphyroptera, Cs. ochroptera). In addition to 43 (probably 44 including Cs. subochrea) out of 46 species previously described for Germany, nine species were collected that had never been documented before. These consisted of five species recently established (Ae. albopictus, Ae. japonicus, Ae. koreicus, An. petragnani, Cs. longiareolata), three species probably introduced on one single occasion only and not established (Ae. aegypti, Ae. berlandi, Ae. pulcritarsis), and a newly described cryptic species of the Anopheles maculipennis complex (An. daciae) that had probably always been present but not been differentiated from its siblings. Two species formerly listed for Germany could not be documented (Ae. cyprius, Ae. nigrinus), while presence is likely for another species (Cs. subochrea), which could not be demonstrated in the monitoring programme as it can neither morphologically nor genetically be reliably distinguished from a closely related species (Cs. annulata) in the female sex. While Cs. annulata males were collected in the present programme, this was not the case with Cs. subochrea. In summary, although some species regarded endemic could not be found during the last 9 years, the number of culicid species that must be considered firmly established in Germany has increased to 51 (assuming Cs. subochrea and Ae. nigrinus are still present) due to several newly emerged ones but also to one species (Ae. cyprius) that must be considered extinct after almost a century without documentation. Most likely, introduction and establishment of the new species are a consequence of globalisation and climate warming, as three of them are native to Asia (Ae. albopictus, Ae. japonicus, Ae. koreicus) and three (Ae. albopictus, An. petragnani, Cs. longiareolata) are relatively thermophilic. Another thermophilic species, Uranotaenia unguiculata, which had been described for southwestern Germany in 1994 and had since been found only at the very site of its first detection, was recently documented at additional localities in the northeastern part of the country. As several mosquito species found in Germany are serious pests or potential vectors of disease agents and should be kept under permanent observation or even be controlled immediately on emergence, the German mosquito monitoring programme has recently been institutionalised and perpetuated.
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Affiliation(s)
- Doreen Werner
- Leibniz Centre for Agricultural Landscape Research, Eberswalder Strasse 84, 15374, Muencheberg, Germany.
| | - Stefan Kowalczyk
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald, Insel Riems, Germany
| | - Helge Kampen
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald, Insel Riems, Germany
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Holicki CM, Ziegler U, Răileanu C, Kampen H, Werner D, Schulz J, Silaghi C, Groschup MH, Vasić A. West Nile Virus Lineage 2 Vector Competence of Indigenous Culex and Aedes Mosquitoes from Germany at Temperate Climate Conditions. Viruses 2020; 12:v12050561. [PMID: 32438619 PMCID: PMC7291008 DOI: 10.3390/v12050561] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 05/15/2020] [Accepted: 05/15/2020] [Indexed: 11/16/2022] Open
Abstract
West Nile virus (WNV) is a widespread zoonotic arbovirus and a threat to public health in Germany since its first emergence in 2018. It has become of particular relevance in Germany in 2019 due to its rapid geographical spread and the detection of the first human clinical cases. The susceptibility of indigenous Culex pipiens (biotypes pipiens and molestus) for a German WNV lineage 2 strain was experimentally compared to that of Serbian Cx. pipiens biotype molestus and invasive German Aedes albopictus. All tested populations proved to be competent laboratory vectors of WNV. Culex pipiens biotype pipiens displayed the highest transmission efficiencies (40.0%–52.9%) at 25 °C. This biotype was also able to transmit WNV at 18 °C (transmission efficiencies of 4.4%–8.3%), proving that temperate climates in Central and Northern Europe may support WNV circulation. Furthermore, due to their feeding behaviors, Cx. pipiens biotype molestus and Ae. albopictus can act as “bridge vectors”, leading to human WNV infections.
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Affiliation(s)
- Cora M. Holicki
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald-Insel Riems, Germany; (C.M.H.); (U.Z.); (J.S.); (M.H.G.)
| | - Ute Ziegler
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald-Insel Riems, Germany; (C.M.H.); (U.Z.); (J.S.); (M.H.G.)
| | - Cristian Răileanu
- Institute of Infectology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald-Insel Riems, Germany; (C.R.); (H.K.); (C.S.)
| | - Helge Kampen
- Institute of Infectology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald-Insel Riems, Germany; (C.R.); (H.K.); (C.S.)
| | - Doreen Werner
- Biodiversity of Aquatic and Semiaquatic Landscape Features, Leibniz-Centre for Agricultural Landscape Research, 15374 Muencheberg, Germany;
| | - Jana Schulz
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald-Insel Riems, Germany; (C.M.H.); (U.Z.); (J.S.); (M.H.G.)
| | - Cornelia Silaghi
- Institute of Infectology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald-Insel Riems, Germany; (C.R.); (H.K.); (C.S.)
| | - Martin H. Groschup
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald-Insel Riems, Germany; (C.M.H.); (U.Z.); (J.S.); (M.H.G.)
| | - Ana Vasić
- Institute of Infectology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald-Insel Riems, Germany; (C.R.); (H.K.); (C.S.)
- Correspondence:
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West Nile Virus Epidemic in Germany Triggered by Epizootic Emergence, 2019. Viruses 2020; 12:v12040448. [PMID: 32326472 PMCID: PMC7232143 DOI: 10.3390/v12040448] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 04/09/2020] [Accepted: 04/13/2020] [Indexed: 01/10/2023] Open
Abstract
One year after the first autochthonous transmission of West Nile virus (WNV) to birds and horses in Germany, an epizootic emergence of WNV was again observed in 2019. The number of infected birds and horses was considerably higher compared to 2018 (12 birds, two horses), resulting in the observation of the first WNV epidemy in Germany: 76 cases in birds, 36 in horses and five confirmed mosquito-borne, autochthonous human cases. We demonstrated that Germany experienced several WNV introduction events and that strains of a distinct group (Eastern German WNV clade), which was introduced to Germany as a single introduction event, dominated mosquito, birds, horse and human-related virus variants in 2018 and 2019. Virus strains in this clade are characterized by a specific-Lys2114Arg mutation, which might lead to an increase in viral fitness. Extraordinary high temperatures in 2018/2019 allowed a low extrinsic incubation period (EIP), which drove the epizootic emergence and, in the end, most likely triggered the 2019 epidemic. Spatiotemporal EIP values correlated with the geographical WNV incidence. This study highlights the risk of a further spread in Germany in the next years with additional human WNV infections. Thus, surveillance of birds is essential to provide an early epidemic warning and thus, initiate targeted control measures.
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