1
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Gothe LMR, Ganzenberg S, Ziegler U, Obiegala A, Lohmann KL, Sieg M, Vahlenkamp TW, Groschup MH, Hörügel U, Pfeffer M. Horses as Sentinels for the Circulation of Flaviviruses in Eastern-Central Germany. Viruses 2023; 15:v15051108. [PMID: 37243194 DOI: 10.3390/v15051108] [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: 03/20/2023] [Revised: 04/27/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
Since 2018, autochthonous West Nile virus (WNV) infections have been regularly reported in eastern-central Germany. While clinically apparent infections in humans and horses are not frequent, seroprevalence studies in horses may allow the tracing of WNV and related flaviviruses transmission, such as tick-borne encephalitis virus (TBEV) and Usutu virus (USUV), and consequently help to estimate the risk of human infections. Hence, the aim of our study was to follow the seropositive ratio against these three viruses in horses in Saxony, Saxony Anhalt, and Brandenburg and to describe their geographic distribution for the year 2021. In early 2022, i.e., before the virus transmission season, sera from 1232 unvaccinated horses were tested using a competitive pan-flavivirus ELISA (cELISA). In order to estimate the true seropositive ratio of infection with WNV, TBEV, and USUV for 2021, positive and equivocal results were confirmed by a virus neutralization test (VNT). In addition, possible risk factors for seropositivity using questionnaires were analyzed using logistic regression based on questionnaires similar to our previous study from 2020. In total, 125 horse sera reacted positive in the cELISA. Based on the VNT, 40 sera showed neutralizing antibodies against WNV, 69 against TBEV, and 5 against USUV. Three sera showed antibodies against more than one virus, and eight were negative based on the VNT. The overall seropositive ratio was 3.3% (95% CI: 2.38-4.40) for WNV, 5.6% (95% CI: 4.44-7.04) for TBEV, and 0.4% (95% CI: 0.14-0.98) for USUV infections. While age and number of horses on the holding were factors predicting TBEV seropositivity, no risk factors were discovered for WNV seropositivity. We conclude that horses are useful sentinels to determine the flavivirus circulation in eastern-central Germany, as long as they are not vaccinated against WNV.
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Affiliation(s)
- Leonard M R Gothe
- Institute of Animal Hygiene and Veterinary Public Health, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany
| | - Stefanie Ganzenberg
- Department for Horses, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany
| | - Ute Ziegler
- Friedrich-Loeffler Institut (FLI), Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, 17493 Greifswald-Insel Riems, Germany
| | - Anna Obiegala
- Institute of Animal Hygiene and Veterinary Public Health, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany
| | - Katharina L Lohmann
- 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
| | - Thomas W Vahlenkamp
- Institute of Virology, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, 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
| | - Uwe Hörügel
- Animal Diseases Fund Saxony, Horse Health Service, 01099 Dresden, Germany
| | - Martin Pfeffer
- Institute of Animal Hygiene and Veterinary Public Health, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany
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2
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Luethy D. Eastern, Western, and Venezuelan Equine Encephalitis and West Nile Viruses: Clinical and Public Health Considerations. Vet Clin North Am Equine Pract 2023; 39:99-113. [PMID: 36737290 DOI: 10.1016/j.cveq.2022.11.007] [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] [Indexed: 02/05/2023] Open
Abstract
The continued recognition and emergence of alphavirus and flavivirus diseases is a growing veterinary and public health concern. As the global environment continues to change, mosquito-borne diseases will continue to evolve and expand. Continued development of readily available vaccines for the prevention of these diseases in humans and animals is essential to controlling epizootics of these diseases. Further research into effective antiviral treatments is also sorely needed. This article describes equine encephalitis viruses with a focus on clinical and public health considerations.
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Affiliation(s)
- Daniela Luethy
- Large Animal Internal Medicine, Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, PO Box 100136, Gainesville, FL 32610, USA.
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3
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Toribio RE. Arboviral Equine Encephalitides. Vet Clin North Am Equine Pract 2022; 38:299-321. [PMID: 35953146 DOI: 10.1016/j.cveq.2022.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
A number of viruses transmitted by biological vectors or through direct contact, air, or ingestion cause neurologic disease in equids. Of interest are viruses of the Togaviridae, Flaviviridae, Rhabdoviridae, Herpesviridae, Bornaviridae, and Bunyaviridae families. Many are classified as arboviruses because they use arthropod vectors, whereas others are transmitted directly via ingestion, inhalation, or integument damage. The goal of this article is to provide an overview on pathophysiologic and clinical aspects of arboviruses of equine importance, including alphaviruses (Togaviridae) and flaviviruses (Flaviviridae).
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Affiliation(s)
- Ramiro E Toribio
- College of Veterinary Medicine, The Ohio State University, 601 Vernon Tharp Street, Columbus, OH 43210, USA.
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4
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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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5
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Desanti-Consoli H, Bouillon J, Chapuis RJJ. Equids' Core Vaccines Guidelines in North America: Considerations and Prospective. Vaccines (Basel) 2022; 10:398. [PMID: 35335029 PMCID: PMC8955191 DOI: 10.3390/vaccines10030398] [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: 12/31/2021] [Revised: 02/24/2022] [Accepted: 03/01/2022] [Indexed: 01/27/2023] Open
Abstract
Vaccination against infectious diseases is a cornerstone of veterinary medicine in the prevention of disease transmission, illness severity, and often death in animals. In North American equine medicine, equine vaccines protecting against tetanus, rabies, Eastern and Western equine encephalomyelitis, and West Nile are core vaccines as these have been classified as having a heightened risk of mortality, infectiousness, and endemic status. Some guidelines differ from the label of vaccines, to improve the protection of patients or to decrease the unnecessary administration to reduce potential side effects. In North America, resources for the equine practitioners are available on the American Association of Equine Practitioners (AAEP) website. Conversely, in small companion animals, peer review materials are regularly published in open access journals to guide the vaccination of dogs and cats. The aims of this review are to present how the vaccine guidelines have been established for small companion animals and horses in North America, to review the equine literature to solidify or contrast the current AAEP guidelines of core vaccines, and to suggest future research directions in the equine vaccine field considering small companion animal strategies and the current available resources in equine literature.
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Affiliation(s)
| | - Juliette Bouillon
- Department of Clinical Sciences, Ross University School of Veterinary Medicine, P.O. Box 334, Basseterre, Saint Kitts and Nevis;
| | - Ronan J. J. Chapuis
- Department of Clinical Sciences, Ross University School of Veterinary Medicine, P.O. Box 334, Basseterre, Saint Kitts and Nevis;
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6
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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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7
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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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8
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Saiz JC, Martín-Acebes MA, Blázquez AB, Escribano-Romero E, Poderoso T, Jiménez de Oya N. Pathogenicity and virulence of West Nile virus revisited eight decades after its first isolation. Virulence 2021; 12:1145-1173. [PMID: 33843445 PMCID: PMC8043182 DOI: 10.1080/21505594.2021.1908740] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
West Nile virus (WNV) is a flavivirus which transmission cycle is maintained between mosquitoes and birds, although it occasionally causes sporadic outbreaks in horses and humans that can result in serious diseases and even death. Since its first isolation in Africa in 1937, WNV had been considered a neglected pathogen until its recent spread throughout Europe and the colonization of America, regions where it continues to cause outbreaks with severe neurological consequences in humans and horses. Although our knowledge about the characteristics and consequences of the virus has increased enormously lately, many questions remain to be resolved. Here, we thoroughly update our knowledge of different aspects of the WNV life cycle: virology and molecular classification, host cell interactions, transmission dynamics, host range, epidemiology and surveillance, immune response, clinical presentations, pathogenesis, diagnosis, prophylaxis (antivirals and vaccines), and prevention, and we highlight those aspects that are still unknown and that undoubtedly require further investigation.
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Affiliation(s)
- Juan-Carlos Saiz
- Department of Biotechnology, National Institute for Agricultural and Food Research and Technology (INIA), Madrid, Spain
| | - Miguel A Martín-Acebes
- Department of Biotechnology, National Institute for Agricultural and Food Research and Technology (INIA), Madrid, Spain
| | - Ana B Blázquez
- Department of Biotechnology, National Institute for Agricultural and Food Research and Technology (INIA), Madrid, Spain
| | - Estela Escribano-Romero
- Department of Biotechnology, National Institute for Agricultural and Food Research and Technology (INIA), Madrid, Spain
| | - Teresa Poderoso
- Molecular Virology Group, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Nereida Jiménez de Oya
- Department of Biotechnology, National Institute for Agricultural and Food Research and Technology (INIA), Madrid, Spain
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9
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Animal and Human Vaccines against West Nile Virus. Pathogens 2020; 9:pathogens9121073. [PMID: 33371384 PMCID: PMC7767344 DOI: 10.3390/pathogens9121073] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/17/2020] [Accepted: 12/17/2020] [Indexed: 12/20/2022] Open
Abstract
West Nile virus (WNV) is a widely distributed enveloped flavivirus transmitted by mosquitoes, which main hosts are birds. The virus sporadically infects equids and humans with serious economic and health consequences, as infected individuals can develop a severe neuroinvasive disease that can even lead to death. Nowadays, no WNV-specific therapy is available and vaccines are only licensed for use in horses but not for humans. While several methodologies for WNV vaccine development have been successfully applied and have contributed to significantly reducing its incidence in horses in the US, none have progressed to phase III clinical trials in humans. This review addresses the status of WNV vaccines for horses, birds, and humans, summarizing and discussing the challenges they face for their clinical advance and their introduction to the market.
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10
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Metz MBC, Olufemi OT, Daly JM, Barba M. Systematic review and meta-analysis of seroprevalence studies of West Nile virus in equids in Europe between 2001 and 2018. Transbound Emerg Dis 2020; 68:1814-1823. [PMID: 33012076 DOI: 10.1111/tbed.13866] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/17/2020] [Accepted: 09/25/2020] [Indexed: 01/10/2023]
Abstract
There is some evidence that West Nile virus (WNV), which causes encephalomyelitis in equids, is an emerging disease in Europe. The aim of this study was to perform a systematic review and meta-analysis to analyse seroprevalence studies of WNV in equids in European countries between 2001 and 2018. Two electronic databases, PubMed and Scopus, were searched for relevant publications published from 2001 to 2018 using predetermined keywords. A total of 1,484 papers were initially found. After applying the eligibility criteria, 39 papers were finally included in the systematic review. Analysis of 28,089 equids from 16 European countries revealed a pooled seroprevalence of 8% (95% CI 5%-12%, p < .001, I2 = 99.3%) in Europe. The pooled seroprevalence was slightly higher in Mediterranean basin countries than other countries and when calculated for samples collected between 2001 and 2009 compared to 2010 to 2018. Differences in study design (e.g. sampling associated with recent outbreaks of WNV) contributed to a high degree of variability among studies. Further studies with harmonized study design and reporting of the results are recommended to better estimate and monitor European seroprevalence of WNV in equids.
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Affiliation(s)
- Marine B C Metz
- Agentes Microbiológicos asociados a la Reproducción Animal (ProVaginBio), Veterinary Faculty, Universidad Cardenal Herrera-CEU, CEU Universities, Valencia, Spain
| | - Olaolu T Olufemi
- School of Veterinary Medicine and Science, University of Nottingham, Nottingham, UK
| | - Janet M Daly
- School of Veterinary Medicine and Science, University of Nottingham, Nottingham, UK
| | - Marta Barba
- Agentes Microbiológicos asociados a la Reproducción Animal (ProVaginBio), Veterinary Faculty, Universidad Cardenal Herrera-CEU, CEU Universities, Valencia, Spain
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11
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Tallmadge RL, Antczak DF, Felippe MJB. Genetics of Immune Disease in the Horse. Vet Clin North Am Equine Pract 2020; 36:273-288. [PMID: 32654783 DOI: 10.1016/j.cveq.2020.03.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Host defenses against infection by viruses, bacteria, fungi, and parasites are critical to survival. It has been estimated that upwards of 7% of the coding genes of mammals function in immunity and inflammation. This high level of genomic investment in defense has resulted in an immune system characterized by extraordinary complexity and many levels of redundancy. Because so many genes are involved with immunity, there are many opportunities for mutations to arise that have negative effects. However, redundancy in the mammalian defense system and the adaptive nature of key immune mechanisms buffer the untoward outcomes of many such deleterious mutations.
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Affiliation(s)
- Rebecca L Tallmadge
- Animal Health Diagnostic Center, College of Veterinary Medicine, Cornell University, 240 Farrier Road, Ithaca, NY 14853, USA
| | - Douglas F Antczak
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, 235 Hungerford Hill Road, Ithaca, NY 14853, USA.
| | - Maria Julia Bevilaqua Felippe
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, 930 Campus Road, Ithaca, NY 14853, USA
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12
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Viral Equine Encephalitis, a Growing Threat to the Horse Population in Europe? Viruses 2019; 12:v12010023. [PMID: 31878129 PMCID: PMC7019608 DOI: 10.3390/v12010023] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/15/2019] [Accepted: 12/17/2019] [Indexed: 12/20/2022] Open
Abstract
Neurological disorders represent an important sanitary and economic threat for the equine industry worldwide. Among nervous diseases, viral encephalitis is of growing concern, due to the emergence of arboviruses and to the high contagiosity of herpesvirus-infected horses. The nature, severity and duration of the clinical signs could be different depending on the etiological agent and its virulence. However, definite diagnosis generally requires the implementation of combinations of direct and/or indirect screening assays in specialized laboratories. The equine practitioner, involved in a mission of prevention and surveillance, plays an important role in the clinical diagnosis of viral encephalitis. The general management of the horse is essentially supportive, focused on controlling pain and inflammation within the central nervous system, preventing injuries and providing supportive care. Despite its high medical relevance and economic impact in the equine industry, vaccines are not always available and there is no specific antiviral therapy. In this review, the major virological, clinical and epidemiological features of the main neuropathogenic viruses inducing encephalitis in equids in Europe, including rabies virus (Rhabdoviridae), Equid herpesviruses (Herpesviridae), Borna disease virus (Bornaviridae) and West Nile virus (Flaviviridae), as well as exotic viruses, will be presented.
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13
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Jiménez de Oya N, Escribano-Romero E, Blázquez AB, Martín-Acebes MA, Saiz JC. Current Progress of Avian Vaccines Against West Nile Virus. Vaccines (Basel) 2019; 7:vaccines7040126. [PMID: 31547632 PMCID: PMC6963603 DOI: 10.3390/vaccines7040126] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 09/19/2019] [Accepted: 09/19/2019] [Indexed: 01/15/2023] Open
Abstract
Birds are the main natural host of West Nile virus (WNV), the worldwide most distributed mosquito-borne flavivirus, but humans and equids can also be sporadic hosts. Many avian species have been reported as susceptible to WNV, particularly corvids. In the case that clinical disease develops in birds, this is due to virus invasion of different organs: liver, spleen, kidney, heart, and mainly the central nervous system, which can lead to death 24–48 h later. Nowadays, vaccines have only been licensed for use in equids; thus, the availability of avian vaccines would benefit bird populations, both domestic and wild ones. Such vaccines could be used in endangered species housed in rehabilitation and wildlife reserves, and in animals located at zoos and other recreational installations, but also in farm birds, and in those that are grown for hunting and restocking activities. Even more, controlling WNV infection in birds can also be useful to prevent its spread and limit outbreaks. So far, different commercial and experimental vaccines (inactivated, attenuated, and recombinant viruses, and subunits and DNA-based candidates) have been evaluated, with various regimens, both in domestic and wild avian species. However, there are still disadvantages that must be overcome before avian vaccination can be implemented, such as its cost-effectiveness for domestic birds since in many species the pathogenicity is low or zero, or the viability of being able to achieve collective immunity in wild birds in freedom. Here, a comprehensive review of what has been done until now in the field of avian vaccines against WNV is presented and discussed.
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Affiliation(s)
- Nereida Jiménez de Oya
- Department of Biotechnology, National Agricultural and Food Research and Technology Institute (INIA), 28040 Madrid, Spain.
| | - Estela Escribano-Romero
- Department of Biotechnology, National Agricultural and Food Research and Technology Institute (INIA), 28040 Madrid, Spain.
| | - Ana-Belén Blázquez
- Department of Biotechnology, National Agricultural and Food Research and Technology Institute (INIA), 28040 Madrid, Spain.
| | - Miguel A Martín-Acebes
- Department of Biotechnology, National Agricultural and Food Research and Technology Institute (INIA), 28040 Madrid, Spain.
| | - Juan-Carlos Saiz
- Department of Biotechnology, National Agricultural and Food Research and Technology Institute (INIA), 28040 Madrid, Spain.
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14
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Kaiser JA, Barrett ADT. Twenty Years of Progress Toward West Nile Virus Vaccine Development. Viruses 2019; 11:E823. [PMID: 31491885 PMCID: PMC6784102 DOI: 10.3390/v11090823] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/26/2019] [Accepted: 08/27/2019] [Indexed: 12/14/2022] Open
Abstract
Although West Nile virus (WNV) has been a prominent mosquito-transmitted infection in North America for twenty years, no human vaccine has been licensed. With a cumulative number of 24,714 neurological disease cases and 2314 deaths in the U.S. since 1999, plus a large outbreak in Europe in 2018 involving over 2000 human cases in 15 countries, a vaccine is essential to prevent continued morbidity, mortality, and economic burden. Currently, four veterinary vaccines are licensed, and six vaccines have progressed into clinical trials in humans. All four veterinary vaccines require multiple primary doses and annual boosters, but for a human vaccine to be protective and cost effective in the most vulnerable older age population, it is ideal that the vaccine be strongly immunogenic with only a single dose and without subsequent annual boosters. Of six human vaccine candidates, the two live, attenuated vaccines were the only ones that elicited strong immunity after a single dose. As none of these candidates have yet progressed beyond phase II clinical trials, development of new candidate vaccines and improvement of vaccination strategies remains an important area of research.
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Affiliation(s)
- Jaclyn A Kaiser
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Alan D T Barrett
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX 77555, USA.
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15
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Abstract
Equine populations worldwide are at increasing risk of infection by viruses transmitted by biting arthropods, including mosquitoes, biting midges (Culicoides), sandflies and ticks. These include the flaviviruses (Japanese encephalitis, West Nile and Murray Valley encephalitis), alphaviruses (eastern, western and Venezuelan encephalitis) and the orbiviruses (African horse sickness and equine encephalosis). This review provides an overview of the challenges faced in the surveillance, prevention and control of the major equine arboviruses, particularly in the context of these viruses emerging in new regions of the world.
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Affiliation(s)
- G E Chapman
- Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - M Baylis
- Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - D Archer
- Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - J M Daly
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, UK
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Durand B, Tran A, Balança G, Chevalier V. Geographic variations of the bird-borne structural risk of West Nile virus circulation in Europe. PLoS One 2017; 12:e0185962. [PMID: 29023472 PMCID: PMC5638290 DOI: 10.1371/journal.pone.0185962] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Accepted: 09/24/2017] [Indexed: 11/18/2022] Open
Abstract
The structural risk of West Nile Disease results from the usual functioning of the socio-ecological system, which may favour the introduction of the pathogen, its circulation and the occurrence of disease cases. Its geographic variations result from the local interactions between three components: (i) reservoir hosts, (ii) vectors, both characterized by their diversity, abundance and competence, (iii) and the socio-economic context that impacts the exposure of human to infectious bites. We developed a model of bird-borne structural risk of West Nile Virus (WNV) circulation in Europe, and analysed the association between the geographic variations of this risk and the occurrence of WND human cases between 2002 and 2014. A meta-analysis of WNV serosurveys conducted in wild bird populations was performed to elaborate a model of WNV seropositivity in European bird species, considered a proxy for bird exposure to WNV. Several eco-ethological traits of bird species were linked to seropositivity and the statistical model adequately fitted species-specific seropositivity data (area under the ROC curve: 0.85). Combined with species distribution maps, this model allowed deriving geographic variations of the bird-borne structural risk of WNV circulation. The association between this risk, and the occurrence of WND human cases across the European Union was assessed. Geographic risk variations of bird-borne structural risk allowed predicting WND case occurrence in administrative districts of the EU with a sensitivity of 86% (95% CI: 0.79-0.92), and a specificity of 68% (95% CI: 0.66-0.71). Disentangling structural and conjectural health risks is important for public health managers as risk mitigation procedures differ according to risk type. The results obtained show promise for the prevention of WND in Europe. Combined with analyses of vector-borne structural risk, they should allow designing efficient and targeted prevention measures.
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Affiliation(s)
- Benoit Durand
- University Paris Est, Anses, Laboratory for Animal Health, Epidemiology Unit, Maisons-Alfort, France
| | - Annelise Tran
- Cirad, UMR TETIS, Montpellier, France
- Cirad, UMR ASTRE, Montpellier, France
| | | | - Véronique Chevalier
- Cirad, UMR ASTRE, Montpellier, France
- Institut Pasteur du Cambodge, Epidemiology and Public Health Unit, Phnom Penh, Cambodia
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17
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Cardinale E, Bernard C, Lecollinet S, Rakotoharinome VM, Ravaomanana J, Roger M, Olive MM, Meenowa D, Jaumally MR, Melanie J, Héraud JM, Zientara S, Cêtre-Sossah C. West Nile virus infection in horses, Indian ocean. Comp Immunol Microbiol Infect Dis 2017; 53:45-49. [PMID: 28750867 DOI: 10.1016/j.cimid.2017.06.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 06/20/2017] [Accepted: 06/23/2017] [Indexed: 11/16/2022]
Abstract
The circulation of West Nile virus (WNV) in horses was investigated in the Southwest Indian ocean. In 2010, blood samples were collected from a total of 303 horses originating from Madagascar, Mauritius, Reunion and the Seychelles and tested for WNV-specific antibodies. An overall seroprevalence of 27.39% was detected in the Indian Ocean with the highest WNV antibody prevalence of 46.22% (95% CI: [37.4-55.2%]) in Madagascar. The age and origin of the horses were found to be associated with the WNV infection risk. This paper presents the first seroprevalence study investigating WN fever in horses in the Southwest Indian Ocean area and indicates a potential risk of infection for humans and animals. In order to gain a better understanding of WN transmission cycles, WNV surveillance needs to be implemented in each of the countries.
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Affiliation(s)
- E Cardinale
- CIRAD, UMR 117 ASTRE, Cyroi Platform, F-97490 Sainte Clotilde, La Réunion, France; INRA, UMR 1309 ASTRE, F-34598 Montpellier, France.
| | - C Bernard
- CIRAD, UMR 117 ASTRE, Cyroi Platform, F-97490 Sainte Clotilde, La Réunion, France; INRA, UMR 1309 ASTRE, F-34598 Montpellier, France
| | - S Lecollinet
- UMR 1161 (ANSES/INRA/ENVA), EU-RL on Equine Diseases, F- 94701 Maisons-Alfort, France
| | - V M Rakotoharinome
- Ministère auprès de la Présidence en charge de l'Agriculture, de l'Elevage, Direction des Services Vétérinaires, Ampandrianomby, Antananarivo, Madagascar
| | - J Ravaomanana
- Centre National de la Recherche Appliquée au Développement Rural (Fofifa), Département de Recherches Zootechniques et Vétérinaires, Antananarivo, Madagascar
| | - M Roger
- CIRAD, UMR 117 ASTRE, Cyroi Platform, F-97490 Sainte Clotilde, La Réunion, France; INRA, UMR 1309 ASTRE, F-34598 Montpellier, France
| | - M M Olive
- CIRAD, UMR 117 ASTRE, Cyroi Platform, F-97490 Sainte Clotilde, La Réunion, France; INRA, UMR 1309 ASTRE, F-34598 Montpellier, France
| | - D Meenowa
- Ministère des Agro-Industries, Réduit, Mauritius
| | - M R Jaumally
- Ministère des Agro-Industries, Réduit, Mauritius
| | - J Melanie
- Ministère de l'Agriculture et des ressources marines, Victoria, Seychelles
| | - J M Héraud
- Institut Pasteur de Madagascar, Unité de Virologie, BP 1274, Antananarivo 101, Madagascar
| | - S Zientara
- UMR 1161 (ANSES/INRA/ENVA), EU-RL on Equine Diseases, F- 94701 Maisons-Alfort, France
| | - C Cêtre-Sossah
- CIRAD, UMR 117 ASTRE, Cyroi Platform, F-97490 Sainte Clotilde, La Réunion, France; INRA, UMR 1309 ASTRE, F-34598 Montpellier, France
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18
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Evaluation of Cross-Protection of a Lineage 1 West Nile Virus Inactivated Vaccine against Natural Infections from a Virulent Lineage 2 Strain in Horses, under Field Conditions. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2015; 22:1040-9. [PMID: 26178384 DOI: 10.1128/cvi.00302-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 07/05/2015] [Indexed: 12/27/2022]
Abstract
Although experimental data regarding cross-protection of horse West Nile virus (WNV) vaccines against lineage 2 infections exist, the cross-protective efficacy of these vaccines under field conditions has not been demonstrated. This study was conducted to evaluate the capability of an inactivated lineage 1 vaccine (Equip WNV) to protect against natural infections from the Nea Santa-Greece-2010 lineage 2 strain. In total, 185 WNV-seronegative horses in Thessaloniki, Greece, were selected during 2 consecutive years (2011 and 2012); 140 were immunized, and 45 were used as controls. Horses were examined for signs compatible with WNV infection. Neutralizing antibody titers against the Greek strain and the PaAn001/France lineage 1 strain were determined in immunized horses. WNV circulation was detected during both years in the study area. It was estimated that 37% and 27% of the horses were infected during 2011 and 2012, respectively. Three control animals developed clinical signs, and the WNV diagnosis was confirmed. Signs related to WNV infection were not observed in the vaccinated animals. The nonvaccinated animals had a 7.58% ± 1.82% higher chance of exhibiting signs than immunized animals (P < 0.05). Neutralizing antibodies raised against both strains in all immunized horses were detectable 1 month after the initial vaccination course. The cross-protective capacity of the lowest titer (1:40) was evident in 19 animals which were subsequently infected and did not exhibit signs. Neutralizing antibodies were detectable until the annual booster, when strong anamnestic responses were observed (geometrical mean titer ratio [GMTR] for lineage 1 of 30.2; GMTR for lineage 2 of 27.5). The results indicate that Equip WNV is capable of inducing cross-protection against natural infections from a virulent lineage 2 WNV strain in horses.
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Ulbert S, Magnusson SE. Technologies for the development of West Nile virus vaccines. Future Microbiol 2015; 9:1221-32. [PMID: 25405890 DOI: 10.2217/fmb.14.67] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
West Nile virus (WNV), an emerging mosquito-borne and zoonotic flavivirus, continues to spread worldwide and represents a major problem for human and veterinary medicine. In recent years, severe outbreaks were observed in the USA and Europe with neighboring countries, and the virus is considered to be endemic in an increasing number of areas. Although most infections remain asymptomatic, WNV can cause severe, even fatal, neurological disease, which affects mostly the elderly and immunocompromised individuals. Several vaccines have been licensed in the veterinary sector, but no human vaccine is available today. This review summarizes recent strategies that are being followed to develop WNV vaccines with emphasis on technologies suitable for the use in humans.
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Affiliation(s)
- Sebastian Ulbert
- Department of Immunology, Fraunhofer Institute for Cell Therapy & Immunology, Perlickstrasse 1, 04103 Leipzig, Germany
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20
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Montgomery RR, Murray KO. Risk factors for West Nile virus infection and disease in populations and individuals. Expert Rev Anti Infect Ther 2015; 13:317-25. [PMID: 25637260 PMCID: PMC4939899 DOI: 10.1586/14787210.2015.1007043] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
West Nile virus (WNV) is a mosquito-borne enveloped positive-strand RNA virus that emerged in North America in 1999 in New York City. Over the past 15 years, WNV has become established throughout the USA and has spread into Canada, Mexico and the Caribbean. CDC reports indicate >41,000 clinical cases, including more than 1700 fatalities. An estimated 3 million people in the USA may have been infected to date. Infection with WNV is dependent on many factors including climate, mosquito habitats and immunologically naïve bird populations. In addition, variations within individuals contribute to the risk of severe disease, in particular, advanced age, hypertension, immunosuppression and critical elements of the immune response. Recent advances in technology now allow detailed analysis of complex immune interactions relevant to disease susceptibility.
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Affiliation(s)
- Ruth R. Montgomery
- Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut 06520
| | - Kristy O. Murray
- Department of Pediatrics, Baylor College of Medicine and Texas Children's Hospital, Houston, TX
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Ergunay K, Gunay F, Erisoz Kasap O, Oter K, Gargari S, Karaoglu T, Tezcan S, Cabalar M, Yildirim Y, Emekdas G, Alten B, Ozkul A. Serological, molecular and entomological surveillance demonstrates widespread circulation of West Nile virus in Turkey. PLoS Negl Trop Dis 2014; 8:e3028. [PMID: 25058465 PMCID: PMC4109882 DOI: 10.1371/journal.pntd.0003028] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 06/06/2014] [Indexed: 11/22/2022] Open
Abstract
West Nile virus (WNV), a mosquito-borne flavivirus with significant impact on human and animal health, has recently demonstrated an expanded zone of activity globally. The aim of this study is to investigate the frequency and distribution of WNV infections in potential vectors and several mammal and avian species in Turkey, where previous data indicate viral circulation. The study was conducted in 15 provinces across Turkey during 2011–2013. In addition, the entomological study was extended to 4 districts of the Turkish Republic of Northern Cyprus. WNV exposure was determined in humans, horses, sheep and ducks from Mersin, Sanliurfa, Van and Kars provinces of Turkey, via the detection of neutralizing antibodies. WNV RNA was sought in human and equine samples from Mersin, Adana and Mugla provinces. Field-collected mosquitoes from 92 sites at 46 locations were characterized morphologically and evaluated for viral RNA. Neutralizing antibodies were identified in 10.5% of the 1180 samples studied and detected in all species evaluated. Viral nucleic acids were observed in 5.9% of 522 samples but only in horses. A total of 2642 mosquito specimens belonging to 15 species were captured, where Ochlerotatus caspius (52.4%), Culex pipiens sensu lato (24.2%) comprise the most frequent species. WNV RNA was detected in 4 mosquito pools (1.9%), that comprise Oc. caspius Cx. pipiens s.l. and DNA barcoding revealed the presence of Cx. quinquefasciatus and Cx. perexiguus mosquitoes in infected Culex pools. All WNV partial sequences were characterized as lineage 1 clade 1a. These findings indicate a widespread WNV activity in Turkey, in Eastern Thrace and Mediterranean-Aegean regions as well as Southeastern and Northeastern Anatolia. West Nile virus (WNV), frequently transmitted to humans and other susceptible species via bites of infected mosquitoes, is a significant global public health threat. Limited information is available on WNV epidemiology in Turkey, located in the endemic zone of the agent around the Mediterranean Sea. This study was performed to reveal WNV activity in potential hosts and vector mosquitoes, involving 11 provinces in Turkey and the Turkish Republic of Northern Cyprus during 2011–2013. Our findings indicate virus exposure in humans and various animals in previously unexplored regions as well as a high rate of virus circulation in equine blood samples during the mosquito season. Field-captured mosquito specimens demonstrated the presence of major WNV vectors among 15 species identified. WNV infection was detected in 1.9% of the pooled mosquito specimens. Molecular characterization of the individual mosquitoes of the infected pools revealed Culex quinquefasciatus and Cx. perexiguus species, important WNV vectors where Culex quinquefasciatus not previously known to exist in Turkey. Partial viral genome sequences obtained from infected hosts were characterized as lineage 1, the predominant pathogenic WNV strain circulating in Europe as well as the American Continent.
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Affiliation(s)
- Koray Ergunay
- Faculty of Medicine, Department of Medical Microbiology, Virology Unit, Hacettepe University, Ankara, Turkey
| | - Filiz Gunay
- Faculty of Sciences, Department of Biology, Division of Ecology, Hacettepe University, Ankara, Turkey
| | - Ozge Erisoz Kasap
- Faculty of Sciences, Department of Biology, Division of Ecology, Hacettepe University, Ankara, Turkey
| | - Kerem Oter
- Faculty of Veterinary Medicine, Department of Parasitology, Istanbul University, Istanbul, Turkey
| | - Sepandar Gargari
- Faculty of Veterinary Medicine, Department of Virology, Ankara University, Ankara, Turkey
| | - Taner Karaoglu
- Faculty of Veterinary Medicine, Department of Virology, Ankara University, Ankara, Turkey
| | - Seda Tezcan
- Faculty of Medicine, Department of Medical Microbiology, Mersin University, Mersin, Turkey
| | - Mehmet Cabalar
- Faculty of Veterinary Medicine, Department of Virology, Harran University, Ankara, Turkey
| | - Yakup Yildirim
- Faculty of Veterinary Medicine, Department of Virology, Kafkas University, Ankara, Turkey
| | - Gürol Emekdas
- Faculty of Medicine, Department of Medical Microbiology, Mersin University, Mersin, Turkey
| | - Bulent Alten
- Faculty of Sciences, Department of Biology, Division of Ecology, Hacettepe University, Ankara, Turkey
| | - Aykut Ozkul
- Faculty of Veterinary Medicine, Department of Virology, Ankara University, Ankara, Turkey
- * E-mail:
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22
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Maclachlan NJ, Henderson C, Schwartz-Cornil I, Zientara S. The immune response of ruminant livestock to bluetongue virus: From type I interferon to antibody. Virus Res 2014; 182:71-7. [DOI: 10.1016/j.virusres.2013.09.040] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 09/28/2013] [Accepted: 09/29/2013] [Indexed: 10/26/2022]
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Chevalier V, Tran A, Durand B. Predictive modeling of West Nile virus transmission risk in the Mediterranean Basin: how far from landing? INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2013; 11:67-90. [PMID: 24362544 PMCID: PMC3924437 DOI: 10.3390/ijerph110100067] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 12/03/2013] [Accepted: 12/04/2013] [Indexed: 12/14/2022]
Abstract
The impact on human and horse health of West Nile fever (WNF) recently and dramatically increased in Europe and neighboring countries. Involving several mosquito and wild bird species, WNF epidemiology is complex. Despite the implementation of surveillance systems in several countries of concern, and due to a lack of knowledge, outbreak occurrence remains unpredictable. Statistical models may help identifying transmission risk factors. When spatialized, they provide tools to identify areas that are suitable for West Nile virus transmission. Mathematical models may be used to improve our understanding of epidemiological process involved, to evaluate the impact of environmental changes or test the efficiency of control measures. We propose a systematic literature review of publications aiming at modeling the processes involved in WNF transmission in the Mediterranean Basin. The relevance of the corresponding models as predictive tools for risk mapping, early warning and for the design of surveillance systems in a changing environment is analyzed.
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Affiliation(s)
- Véronique Chevalier
- Cirad, UPR AGIRs, Montpellier F-34398, France
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +33-4-6759-3706; Fax: +33-4-6759-3754
| | - Annelise Tran
- Cirad, UPR AGIRs, Montpellier F-34398, France
- Cirad, UMR TETIS, Montpellier F-34398, France; E-Mail:
| | - Benoit Durand
- Anses, Epidemiology Unit, Laboratoire de Santé Animale, Université Paris-Est, Maisons-Alfort F-94706, France; E-Mail:
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CD8 and CD4 T cells in west nile virus immunity and pathogenesis. Viruses 2013; 5:2573-84. [PMID: 24153060 PMCID: PMC3814605 DOI: 10.3390/v5102573] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 10/05/2013] [Accepted: 10/14/2013] [Indexed: 01/06/2023] Open
Abstract
CD4 and CD8 T lymphocytes are adaptive immune cells that play a key role in the immune response to pathogens. They have been extensively studied in a variety of model systems and the mechanisms by which they function are well described. However, the responses by these cell types vary widely from pathogen to pathogen. In this review, we will discuss the role of CD8 and CD4 T cells in the immune response to West Nile virus infection.
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25
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West Nile viral infection of equids. Vet Microbiol 2013; 167:168-80. [PMID: 24035480 DOI: 10.1016/j.vetmic.2013.08.013] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 08/15/2013] [Accepted: 08/16/2013] [Indexed: 12/14/2022]
Abstract
West Nile virus (WNV) is a flavivirus transmitted between certain species of birds and mosquito vectors. Tangential infections of equids and subsequent equine epizootics have occurred historically. Although the attack rate has been estimated to be below 10%, mortality rates can approach 50% in horses that present clinical disease. Symptoms are most commonly presenting in the form of encephalitis with ataxia as well as limb weakness, recumbency and muscle fasciculation. The most effective strategy for prevention of equine disease is proper vaccination with one of the numerous commercially available vaccines available in North America or the European Union. Recently, WNV has been increasingly associated with equine epizootics resulting from novel non-lineage-1a viruses in expanding geographic areas. However, specific experimental data on the virulence of these novel virus strains is lacking and questions remain as to the etiology of the expanded epizootics: whether it be a function of inherent virulence or ecological and/or climactic factors that could precipitate the altered epidemiological patterns observed.
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26
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Minke J, Siger L, Cupillard L, Powers B, Bakonyi T, Boyum S, Nowotny N, Bowen R. Protection provided by a recombinant ALVAC®-WNV vaccine expressing the prM/E genes of a lineage 1 strain of WNV against a virulent challenge with a lineage 2 strain. Vaccine 2011; 29:4608-12. [DOI: 10.1016/j.vaccine.2011.04.058] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 04/11/2011] [Accepted: 04/17/2011] [Indexed: 11/29/2022]
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Abstract
West Nile virus (WNV) is a zoonotic virus that circulates in birds and is transmitted by mosquitoes. Incidentally, humans, horses and other mammals can also be infected. Disease symptoms caused by WNV range from fever to neurological complications, such as encephalitis or meningitis. Mortality is observed mostly in older and immunocompromised individuals. In recent years, epidemics caused by WNV in humans and horses have become more frequent in several Southern European countries, such as Italy and Greece. In 1999, WNV was introduced into the USA and spread over North America within a couple of years. The increasing number of WNV outbreaks is associated with the emergence of novel viral strains, which display higher virulence and greater epidemic potential for humans. Upon infection with WNV, the mammalian immune system counteracts the virus at several different levels. On the other side, WNV has developed elaborated escape mechanisms to avoid its elimination. This review summarizes recent findings in WNV research that help to understand the complex biology associated with this emerging pathogen.
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Affiliation(s)
- Sebastian Ulbert
- Vaccine Technologies Unit, Fraunhofer Institute of Cell Therapy and Immunology, Leipzig, Germany. Sebastian.ulbert @ izi.fraunhofer.de
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28
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Artsob H, Gubler DJ, Enria DA, Morales MA, Pupo M, Bunning ML, Dudley JP. West Nile Virus in the New World: trends in the spread and proliferation of West Nile Virus in the Western Hemisphere. Zoonoses Public Health 2011; 56:357-69. [PMID: 19486320 DOI: 10.1111/j.1863-2378.2008.01207.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The observed patterns and variations in the ecology, epidemiology, distribution and prevalence of the West Nile Virus (WNV) in different areas of the Western Hemisphere make this pathogen of particular importance as a model for understanding the potential risk factors associated with emerging pathogens worldwide, particularly those involving zoonotic pathogens whose epidemiology involves the potential for vertical transmission in arthropod vector species, and horizontal and vertical transmission within and among vertebrate host species. Record numbers of human WNV cases were recorded in Canada during 2007, with >50% more cases than documented in any previous year. Although overall numbers of human infections recorded in the United States were not exceptionally high during 2007 relative to epidemic levels reported in 2002 and 2003, the state of Oklahoma reported that the highest-ever number of human WNV cases and the numbers of human cases recorded in Canada were 50% higher than previous record levels recorded in 2003. The record and near-record numbers of human WNV infections recorded in several regions of North America during 2007 have important implications for the future management and surveillance of WNV vectors and reservoirs in North America. The spatiotemporal distribution of WNV infections in humans and animals recorded during 2007 in North America and South America have important implications for the surveillance and management of public health threats from WNV in the Western Hemisphere. Serological surveys conducted in areas of intense WNV transmission in the United States have reported low prevalence of antibodies to WNV in human s populations, indicating that additional epidemic outbreaks of human disease from WNV can be expected in the future.
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Affiliation(s)
- H Artsob
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada.
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Laperriere V, Brugger K, Rubel F. Simulation of the seasonal cycles of bird, equine and human West Nile virus cases. Prev Vet Med 2011; 98:99-110. [DOI: 10.1016/j.prevetmed.2010.10.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Revised: 10/22/2010] [Accepted: 10/25/2010] [Indexed: 10/18/2022]
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30
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Investigation of antigen specific lymphocyte responses in healthy horses vaccinated with an inactivated West Nile virus vaccine. Vet Immunol Immunopathol 2008; 126:293-301. [DOI: 10.1016/j.vetimm.2008.08.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2007] [Revised: 07/25/2008] [Accepted: 08/18/2008] [Indexed: 11/30/2022]
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31
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Shrestha B, Ng T, Chu HJ, Noll M, Diamond MS. The relative contribution of antibody and CD8+ T cells to vaccine immunity against West Nile encephalitis virus. Vaccine 2008; 26:2020-33. [PMID: 18339459 DOI: 10.1016/j.vaccine.2008.02.009] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2007] [Revised: 01/23/2008] [Accepted: 02/04/2008] [Indexed: 12/30/2022]
Abstract
West Nile virus (WNV) is a mosquito borne, neurotropic flavivirus that causes a severe central nervous system (CNS) infection in humans and animals. Although commercial vaccines are available for horses, none is currently approved for human use. In this study, we evaluated the efficacy and mechanism of immune protection of two candidate WNV vaccines in mice. A formalin-inactivated WNV vaccine induced higher levels of specific and neutralizing antibodies compared to a DNA plasmid vaccine that produces virus-like particles. Accordingly, partial and almost complete protection against a highly stringent lethal intracranial WNV challenge were observed in mice 60 days after single dose immunization with the DNA plasmid and inactivated virus vaccines, respectively. In mice immunized with a single dose of DNA plasmid or inactivated vaccine, antigen-specific CD8(+) T cells were induced and contributed to protective immunity as acquired or genetic deficiencies of CD8(+) T cells lowered the survival rates. In contrast, in boosted animals, WNV-specific antibody titers were higher, survival rates after challenge were greater, and an absence of CD8(+) T cells did not appreciably affect mortality. Overall, our experiments suggest that in mice, both inactivated WNV and DNA plasmid vaccines are protective after two doses, and the specific contribution of antibody and CD8(+) T cells to vaccine immunity against WNV is modulated by the prime-boost strategy.
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Affiliation(s)
- Bimmi Shrestha
- Department of Medicine, 660 S. Euclid Avenue, Box 8051, Washington University School of Medicine, St. Louis, MO 63110, United States
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32
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Epp T, Waldner C, Townsend HGG. A case-control study of factors associated with development of clinical disease due to West Nile virus, Saskatchewan 2003. Equine Vet J 2008; 39:498-503. [PMID: 18065306 DOI: 10.2746/042516407x248476] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
REASON FOR PERFORMING STUDY West Nile virus (WNV) was first diagnosed in Saskatchewan equids in 2002. AWNV epidemic was considered highly likely for 2003, which would provide a unique opportunity to study all aspects of WNV subclinical infection and clinical disease development in a relatively naive population. HYPOTHESIS There are individual equid attributes and management risk factors associated with development of clinical disease. Specifically, this study could address the question of vaccine efficacy for the prevention of development of clinical disease. METHODS A case-control study was conducted in the summer of 2003 during a province-wide outbreak of WNV. Between 5 and 10 equids were sampled from each of 23 case premises with clinical disease and 23 control premises with no apparent or confirmed clinical disease. Data were analysed to identify risk factors for the development of clinical disease. RESULTS The proportion of equids serologically positive for natural exposure to West Nile virus was 64% (193/300). Nonvaccinated equids were 23 times (95%CI limits 3.0, 168.5, P = 0.002) more likely to develop clinical disease than those vaccinated. The estimate of vaccine efficacy in this field study was 96% (95%CI limits 67%, 99%). CONCLUSIONS The study demonstrated that vaccination was strongly associated with the prevention of clinical disease. POTENTIAL RELEVANCE Vaccination is an effective, practical method of prevention of clinical disease.
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Affiliation(s)
- T Epp
- Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4, Canada
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Safety and efficacy in geese of a PER.C6-based inactivated West Nile virus vaccine. Vaccine 2007; 25:8338-45. [DOI: 10.1016/j.vaccine.2007.09.055] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Revised: 09/04/2007] [Accepted: 09/15/2007] [Indexed: 11/19/2022]
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Seino KK, Long MT, Gibbs EPJ, Bowen RA, Beachboard SE, Humphrey PP, Dixon MA, Bourgeois MA. Comparative efficacies of three commercially available vaccines against West Nile Virus (WNV) in a short-duration challenge trial involving an equine WNV encephalitis model. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2007; 14:1465-71. [PMID: 17687109 PMCID: PMC2168174 DOI: 10.1128/cvi.00249-07] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We used a severe challenge model that produces clinical West Nile virus (WNV) disease to test the efficacy of three commercially available equine WNV vaccines in horses. Twenty-four healthy, WNV-seronegative horses of varying ages and genders were placed, in random and blind manner, into three trial groups consisting of eight horses each; two horses in each group received (i) an inactivated WNV vaccine (K-WN), (ii) a modified-live vaccine (CP-WN) containing the WNV prM and E proteins expressed by a canarypox vector, (iii) a live-chimera vaccine (WN-FV) containing WNV prM and E proteins expressed in a YF17D vector, or (iv) a diluent control. Challenge by this model caused grave neurological signs, viremia, moderate to severe histopathologic lesions in the brain and spinal cord, and an outcome of 0% survivorship in all six control horses. In contrast, challenge in horses at between 28 days postvaccination with the chimera vaccine and 56 days postvaccination with the commercial inactivated or modified-live vaccine resulted in 100% survivorship (protection from the onset of WNV encephalitis and viremia). Horses vaccinated with the live-chimera vaccine showed significantly fewer clinical signs than did the control horses (P </= 0.01) and the horses vaccinated with inactivated vaccine (P = 0.035). Mild residual inflammatory lesions were seen in a few of the vaccinated horses.
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Affiliation(s)
- K K Seino
- College of Veterinary Medicine, University of Florida, 2015 SW 16th Avenue, Gainesville, FL 32610, USA.
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MacLachlan NJ, Balasuriya UB, Davis NL, Collier M, Johnston RE, Ferraro GL, Guthrie AJ. Experiences with new generation vaccines against equine viral arteritis, West Nile disease and African horse sickness. Vaccine 2007; 25:5577-82. [PMID: 17267078 DOI: 10.1016/j.vaccine.2006.12.058] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2006] [Revised: 12/13/2006] [Accepted: 12/28/2006] [Indexed: 11/23/2022]
Abstract
Viral diseases constitute an ever growing threat to the horse industry worldwide because of the rapid movement of large numbers of horses for competition and breeding. A number of different types of vaccines are available for protective immunization of horses against viral diseases. Traditional inactivated and live-attenuated (modified live virus, MLV) virus vaccines remain popular and efficacious but recombinant vaccines are increasingly being developed and used, in part because of the perceived deficiencies of some existing products. New generation vaccines include MLVs with deletions and/or mutations of critical genes, subunit vaccines that incorporate immunogenic proteins (or portions thereof) or expression vectors that produce these proteins as immunogens, and DNA vaccines. New generation vaccines have been developed for several viral diseases of horses. We recently have developed an alphavirus replicon-vectored equine arteritis virus (EAV) vaccine, and evaluated a commercial canary pox virus-vectored vaccine for West Nile disease. The success of these new-generation vaccines has catalyzed efforts to develop improved vaccines for the prevention of African horse sickness, a disease of emerging global significance.
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Affiliation(s)
- N James MacLachlan
- Equine Viral Disease Laboratory, Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
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