1
|
Naveed A, Eertink LG, Wang D, Li F. Lessons Learned from West Nile Virus Infection:Vaccinations in Equines and Their Implications for One Health Approaches. Viruses 2024; 16:781. [PMID: 38793662 PMCID: PMC11125849 DOI: 10.3390/v16050781] [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: 03/11/2024] [Revised: 05/03/2024] [Accepted: 05/09/2024] [Indexed: 05/26/2024] Open
Abstract
Humans and equines are two dead-end hosts of the mosquito-borne West Nile virus (WNV) with similar susceptibility and pathogenesis. Since the introduction of WNV vaccines into equine populations of the United States of America (USA) in late 2002, there have been only sporadic cases of WNV infection in equines. These cases are generally attributed to unvaccinated and under-vaccinated equines. In contrast, due to the lack of a human WNV vaccine, WNV cases in humans have remained steadily high. An average of 115 deaths have been reported per year in the USA since the first reported case in 1999. Therefore, the characterization of protective immune responses to WNV and the identification of immune correlates of protection in vaccinated equines will provide new fundamental information about the successful development and evaluation of WNV vaccines in humans. This review discusses the comparative epidemiology, transmission, susceptibility to infection and disease, clinical manifestation and pathogenesis, and immune responses of WNV in humans and equines. Furthermore, prophylactic and therapeutic strategies that are currently available and under development are described. In addition, the successful vaccination of equines against WNV and the potential lessons for human vaccine development are discussed.
Collapse
Affiliation(s)
| | | | | | - Feng Li
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY 40546, USA; (A.N.); (L.G.E.); (D.W.)
| |
Collapse
|
2
|
Schwarz ER, Long MT. Comparison of West Nile Virus Disease in Humans and Horses: Exploiting Similarities for Enhancing Syndromic Surveillance. Viruses 2023; 15:1230. [PMID: 37376530 DOI: 10.3390/v15061230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/22/2023] [Accepted: 05/23/2023] [Indexed: 06/29/2023] Open
Abstract
West Nile virus (WNV) neuroinvasive disease threatens the health and well-being of horses and humans worldwide. Disease in horses and humans is remarkably similar. The occurrence of WNV disease in these mammalian hosts has geographic overlap with shared macroscale and microscale drivers of risk. Importantly, intrahost virus dynamics, the evolution of the antibody response, and clinicopathology are similar. The goal of this review is to provide a comparison of WNV infection in humans and horses and to identify similarities that can be exploited to enhance surveillance methods for the early detection of WNV neuroinvasive disease.
Collapse
Affiliation(s)
- Erika R Schwarz
- Montana Veterinary Diagnostic Laboratory, MT Department of Livestock, Bozeman, MT 59718, USA
| | - Maureen T Long
- Department of Comparative, Diagnostic, & Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA
| |
Collapse
|
3
|
Lohmann KL, Sieg M, Landmann M, Ganzenberg S, Arnold C, Vahlenkamp T, Ulrich RG. West-Nil-Virus-Infektion bei 12 Pferden in Mitteldeutschland. Tierarztl Prax Ausg G Grosstiere Nutztiere 2022; 50:362-376. [DOI: 10.1055/a-1965-0307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Zusammenfassung
Gegenstand und Ziel Die Vorstellungsgründe, klinische Symptomatik, Diagnostik, Therapie und Ergebnis der Therapie von 12 Pferden mit klinisch apparenter West-Nil-Virus (WNV)-Infektion werden beschrieben.
Material und Methoden Fallserie
Ergebnisse Die adulten Pferde (Alter 6–18 Jahre, 7 Stuten, 5 Wallache) aus Sachsen oder Sachsen-Anhalt wurden zwischen September 2018 und September 2020 mit unterschiedlichen Vorberichten vorgestellt. Alle Pferde wurden im August oder September vorgestellt und keines der Pferde war gegen das WNV geimpft. Fieber war das häufigste Allgemeinsymptom und trat bei 8/12 Pferden auf. An neurologischen Symptomen traten Muskelfaszikulationen (11/12 Pferde), Ataxie (8/12 Pferde) sowie Hyperästhesie und Kopfschiefhaltung (je 6/12 Pferde) am häufigsten auf. Bei allen Pferden wurde die Infektion mittels Nachweises von IgM sowie neutralisierenden Antikörpern gegen das WNV diagnostiziert, zwei euthanasierte Pferde waren zudem PCR-positiv. Die symptomatische Therapie beinhaltete vor allem nicht-steroidale Antiphlogistika oder Dexamethason sowie Infusionstherapie. Die Dauer des Klinikaufenthaltes betrug im Durchschnitt 7,5 Tage. Sieben Pferde erholten sich laut Besitzerangaben vollständig, für 2 Pferde war keine Information erhältlich.
Schlussfolgerungen und klinische Relevanz Die WNV-Enzephalomyelitis muss in Mitteldeutschland seit 2018 als Differentialdiagnose von im Sommer und Spätsommer auftretenden akuten neurologischen Erkrankungen ungeimpfter Pferdes in Betracht gezogen werden. Die beschriebenen Symptome sowie das Ergebnis der Therapie sind weitgehend deckungsgleich mit Berichten aus Nordamerika und anderen europäischen Ländern.
Collapse
Affiliation(s)
| | - Michael Sieg
- Institut für Virologie, Veterinärmedizinische Fakultät, Universität Leipzig
| | - Maria Landmann
- Institut für Veterinär-Pathologie, Veterinärmedizinische Fakultät, Universität Leipzig
| | | | - Corinna Arnold
- Klinik für Pferde, Veterinärmedizinische Fakultät, Universität Leipzig
| | - Thomas Vahlenkamp
- Institut für Virologie, Veterinärmedizinische Fakultät, Universität Leipzig
| | - Reiner Georg Ulrich
- Institut für Veterinär-Pathologie, Veterinärmedizinische Fakultät, Universität Leipzig
| |
Collapse
|
4
|
Fehér OE, Fehérvári P, Tolnai CH, Forgách P, Malik P, Jerzsele Á, Wagenhoffer Z, Szenci O, Korbacska-Kutasi O. Epidemiology and Clinical Manifestation of West Nile Virus Infections of Equines in Hungary, 2007-2020. Viruses 2022; 14:v14112551. [PMID: 36423160 PMCID: PMC9694158 DOI: 10.3390/v14112551] [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: 10/06/2022] [Revised: 11/06/2022] [Accepted: 11/15/2022] [Indexed: 11/19/2022] Open
Abstract
West Nile virus (WNV) is an emerging pathogen in Hungary, causing severe outbreaks in equines and humans since 2007. The aim of our study was to provide a comprehensive report on the clinical signs of West Nile neuroinvasive disease (WNND) in horses in Hungary. Clinical details of 124 confirmed equine WNND cases were collected between 2007 and 2019. Data about the seasonal and geographical presentation, demographic data, clinical signs, treatment protocols, and disease progression were evaluated. Starting from an initial case originating from the area of possible virus introduction by migratory birds, the whole country became endemic with WNV over the subsequent 12 years. The transmission season did not expand significantly during the data collection period, but vaccination protocols should be always reviewed according to the recent observations. There was not any considerable relationship between the occurrence of WNND and age, breed, or gender. Ataxia was by far the most common neurologic sign related to the disease, but weakness, behavioral changes, and muscle fasciculation appeared frequently. Apart from recumbency combined with inappetence, no other clinical sign or treatment regime correlated with survival. The survival rate showed a moderate increase throughout the years, possibly due to the increased awareness of practitioners.
Collapse
Affiliation(s)
- Orsolya Eszter Fehér
- Institute for Animal Breeding, Nutrition and Laboratory Animal Science, University of Veterinary Medicine, István utca 2, 1078 Budapest, Hungary
- Correspondence:
| | - Péter Fehérvári
- Department of Biomathematics and Informatics, University of Veterinary Medicine, István utca 2, 1078 Budapest, Hungary
- Centre for Translational Medicine, Semmelweis University, 1085 Budapest, Hungary
| | - Csenge Hanna Tolnai
- University Equine Clinic, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Wien, Austria
| | - Petra Forgách
- Department of Microbiology and Infectious Diseases, University of Veterinary Medicine, Hungária Krt. 23-25, 1143 Budapest, Hungary
| | - Péter Malik
- National Food Chain Safety Office, Veterinary Diagnostic Directorate, Tábornok u. 2., 1143 Budapest, Hungary
| | - Ákos Jerzsele
- Department of Pharmacology and Toxicology, University of Veterinary Medicine, István utca 2, 1078 Budapest, Hungary
- National Laboratory of Infectious Animal Diseases, Antimicrobial Resistance, Veterinary Public Health and Food Chain Safety, University of Veterinary Medicine Budapest, István utca 2, 1078 Budapest, Hungary
| | - Zsombor Wagenhoffer
- Institute for Animal Breeding, Nutrition and Laboratory Animal Science, University of Veterinary Medicine, István utca 2, 1078 Budapest, Hungary
| | - Otto Szenci
- Department of Obstetrics and Food Animal Medicine Clinic, University of Veterinary Medicine, István utca 2, 1078 Budapest, Hungary
| | - Orsolya Korbacska-Kutasi
- Institute for Animal Breeding, Nutrition and Laboratory Animal Science, University of Veterinary Medicine, István utca 2, 1078 Budapest, Hungary
- University Equine Clinic, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Wien, Austria
| |
Collapse
|
5
|
Cavalleri JV, Korbacska‐Kutasi O, Leblond A, Paillot R, Pusterla N, Steinmann E, Tomlinson J. European College of Equine Internal Medicine consensus statement on equine flaviviridae infections in Europe. Vet Med (Auckl) 2022; 36:1858-1871. [DOI: 10.1111/jvim.16581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 10/19/2022] [Indexed: 11/13/2022]
Affiliation(s)
- Jessika‐M. V. Cavalleri
- Clinical Unit of Equine Internal Medicine, Department for Companion Animals and Horses University of Veterinary Medicine Vienna Vienna Austria
| | - Orsolya Korbacska‐Kutasi
- Clinical Unit of Equine Internal Medicine, Department for Companion Animals and Horses University of Veterinary Medicine Vienna Vienna Austria
- Department for Animal Breeding, Nutrition and Laboratory Animal Science University of Veterinary Medicine Budapest Hungary
- Hungarian Academy of Sciences—Szent Istvan University (MTA‐SZIE) Large Animal Clinical Research Group Üllő Dóra major Hungary
| | - Agnès Leblond
- EPIA, UMR 0346, Epidemiologie des maladies animales et zoonotiques, INRAE, VetAgro Sup University of Lyon Marcy l'Etoile France
| | - Romain Paillot
- School of Equine and Veterinary Physiotherapy Writtle University College Chelmsford UK
| | - Nicola Pusterla
- Department of Medicine and Epidemiology, School of Veterinary Medicine University of California Davis California USA
| | - Eike Steinmann
- Department of Molecular and Medical Virology, Faculty of Medicine Ruhr University Bochum Bochum Germany
| | - Joy Tomlinson
- Baker Institute for Animal Health Cornell University College of Veterinary Medicine Ithaca New York USA
| |
Collapse
|
6
|
Pathologic Conditions of the Nervous System in Horses. Vet Clin North Am Equine Pract 2022; 38:427-443. [PMID: 35810149 DOI: 10.1016/j.cveq.2022.04.006] [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: 11/23/2022] Open
Abstract
The variety of neurologic diseases which affect horses makes pathologic examination of the nervous system a complex and lengthy process. An understanding of the common causes of neurologic disease, antemortem neurolocalization, and supplementation of the necropsy examination with ancillary testing will help to diagnose a large number of causes of neurologic disease. A general understanding of neuropathology and collaborative relationship with your local pathologists will aid in the definitive diagnosis of neurologic diseases.
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
Castro-Jorge LAD, Siconelli MJL, Ribeiro BDS, Moraes FMD, Moraes JBD, Agostinho MR, Klein TM, Floriano VG, Fonseca BALD. West Nile virus infections are here! Are we prepared to face another flavivirus epidemic? Rev Soc Bras Med Trop 2019; 52:e20190089. [PMID: 30942263 DOI: 10.1590/0037-8682-0089-2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 02/26/2019] [Indexed: 01/29/2023] Open
Abstract
Emerging arthropod-borne viruses (arboviruses), such as chikungunya and Zika viruses, are a major threat to public health in countries like Brazil where biodiversity is high and medical care is sometimes precarious. West Nile fever is a disease caused by the West Nile Virus (WNV), an RNA virus belonging to the Flaviviridae family. It is transmitted by infected mosquitoes to numerous animals like birds, reptiles and mammals, including human and non-human primates. In the last decade, the number of reported cases of WNV infection in humans and animals has increased in the Americas. Circulation of WNV in forests and rural areas in Brazil has been detected based on serological surveys and, in 2014, the first case of West Nile fever was confirmed in a patient from Piauí State. In 2018, the virus was isolated for the first time from a horse from a rural area in the state of Espírito Santo presenting with a neurological disorder; this raises the possibility that other cases of WNV encephalitis may have occurred without clinical recognition and without laboratory diagnosis by specific assays. The imminent WNV outbreak poses a challenge for Brazilian clinicians and researchers. In this review, we summarize the basic biological and ecological characteristics of this virus and the clinical presentation and treatment of febrile illnesses caused by WNV. We also discuss the epidemiological aspects, prophylaxis of WNV infections, and monitoring strategies that could be applied in the possibility of a WNV outbreak in Brazil.
Collapse
Affiliation(s)
- Luiza Antunes de Castro-Jorge
- Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - Márcio Junio Lima Siconelli
- Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - Beatriz Dos Santos Ribeiro
- Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - Flávia Masson de Moraes
- Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - Jonathan Ballico de Moraes
- Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - Mayara Rovariz Agostinho
- Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - Taline Monteiro Klein
- Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - Vitor Gonçalves Floriano
- Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | | |
Collapse
|
10
|
More S, Bøtner A, Butterworth A, Calistri P, Depner K, Edwards S, Garin‐Bastuji B, Good M, Gortázar Schmidt C, Michel V, Miranda MA, Nielsen SS, Raj M, Sihvonen L, Spoolder H, Stegeman JA, Thulke H, Velarde A, Willeberg P, Winckler C, Baldinelli F, Broglia A, Dhollander S, Beltrán‐Beck B, Kohnle L, Morgado J, Bicout D. Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): West Nile fever. EFSA J 2017; 15:e04955. [PMID: 32625621 PMCID: PMC7009844 DOI: 10.2903/j.efsa.2017.4955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
West Nile fever (WNF) has been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of Article 7 on disease profile and impacts, Article 5 on the eligibility of WNF to be listed, Article 9 for the categorisation of WNF according to disease prevention and control rules as in Annex IV and Article 8 on the list of animal species related to WNF. The assessment has been performed following a methodology composed of information collection and compilation, expert judgement on each criterion at individual and, if no consensus was reached before, also at collective level. The output is composed of the categorical answer, and for the questions where no consensus was reached, the different supporting views are reported. Details on the methodology used for this assessment are explained in a separate opinion. According to the assessment performed, WNF can be considered eligible to be listed for Union intervention as laid down in Article 5(3) of the AHL. The disease would comply with the criteria as in Sections 2 and 5 of Annex IV of the AHL, for the application of the disease prevention and control rules referred to in points (b) and (e) of Article 9(1). The animal species to be listed for WNF according to Article 8(3) criteria are several orders of birds and mammals as susceptible species and several families of birds as reservoir. Different mosquito species can serve as vectors.
Collapse
|
11
|
Del Piero F, Stremme DW, Habecker PL, Cantile C. West Nile Flavivirus Polioencephalomyelitis in a Harbor Seal (Phoca vitulina). Vet Pathol 2016; 43:58-61. [PMID: 16407488 DOI: 10.1354/vp.43-1-58] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A 12-year-old male harbor seal presented with progressive signs of neurologic dysfunction including head tremors, muzzle twitching, clonic spasms, and weakness. Lesions included polioenceph-alomyelitis with glial nodules, spheroids, neuronophagia, ring hemorrhages, and a few neutrophils. Neurons, fibers, and glial nodules were multifocally colonized with intracytoplasmic West Nile flavivirus antigens that were demonstrated using indirect immunohistochemical analysis. Flavivirus on cultured cells also was isolated and was identified by use of monoclonal antibodies and reverse transcriptase-polymerase chain reaction analysis. Clinical signs of disease and lesion morphology and distribution were similar to those of equine West Nile virus infection. Similar to horses, alpacas, humans, dogs, and reptiles, seals can be dead-end hosts of West Nile virus.
Collapse
Affiliation(s)
- F Del Piero
- University of Pennsylvania, School of Veterinary Medicine, New Bolton Center, 382 West Street Road, Kennett Square, PA 19348, USA.
| | | | | | | |
Collapse
|
12
|
Balasuriya UBR, Shi PY, Wong SJ, Demarest VL, Gardner IA, Hullinger PJ, Ferraro GL, Boone JD, De Cino CL, Glaser AL, Renshaw RW, Ledizet M, Koski RA, MacLachlan NJ. Detection of Antibodies to West Nile Virus in Equine Sera Using Microsphere Immunoassay. J Vet Diagn Invest 2016; 18:392-5. [PMID: 16921881 DOI: 10.1177/104063870601800413] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
One hundred and ninety-one sera from horses that recently were exposed to West Nile virus (WNV) by either vaccination or natural infection or that were not vaccinated and remained free of infection were used to evaluate fluorescent microsphere immunoassays (MIAs) incorporating recombinant WNV envelope protein (rE) and recombinant nonstructural proteins (rNS1, rNS3, and rNS5) for detection of equine antibodies to WNV. The rE MIA had a diagnostic sensitivity and specificity, respectively, of 99.3% and 97.4% for detection of WNV antibodies in the serum of horses that were recently vaccinated or naturally infected with WNV, as compared to the plaque reduction neutralization test (PRNT). The positive rE MIA results were assumed to be WNV-specific because of the close agreement between this assay and the PRNT and the fact that unvaccinated control horses included in this study were confirmed to be free of exposure to the related St Louis encephalitis virus. The NS protein–based MIA were all less sensitive than either the rE MIA or PRNT (sensitivity 0–48.0), although the rNS1 MIA distinguished horses vaccinated with the recombinant WNV vaccine from those that were immunized with the inactivated WNV vaccine ( P < 0.0001) or naturally infected with WNV ( P < 0.0001). The rE MIA would appear to provide a rapid, convenient, inexpensive, and accurate test for the screening of equine sera for the presence of antibodies to WNV.
Collapse
Affiliation(s)
- Udeni B R Balasuriya
- Equine Viral Disease Laboratory, Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Kleiboeker SB, Loiacono CM, Rottinghaus A, Pue HL, Johnson GC. Diagnosis of West Nile Virus Infection in Horses. J Vet Diagn Invest 2016; 16:2-10. [PMID: 14974840 DOI: 10.1177/104063870401600102] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The North American West Nile virus (WNV) epizootic, which began in 1999, has caused significant morbidity and mortality in horses. Because experimental infection has failed to consistently produce encephalitis in inoculated horses, investigation of naturally occurring cases was used to optimize strategies for diagnosis of this disease. Although WNV RNA could be detected by reverse transcriptase—polymerase chain reaction (RT-PCR) performed on whole blood collected from both clinically affected horses and unaffected herdmates, the diagnostic sensitivity of this approach was low compared with IgM-capture enzyme-linked immunosorbent assay. In addition, it was observed that 18.5% of herdmates of clinically ill horses seroconverted to WNV yet exhibited no overt clinical signs of WNV encephalitis. West Nile viral RNA was detected in neural tissue of 46 of 64 dead horses that were suspected of having WNV encephalitis. Some of these animals were IgM negative or had not been tested serologically. A primary cause of death other than WNV encephalitis was identified in 15 of the 64 cases, whereas the final diagnosis for 3 of these cases remains unresolved. Quantitative RT-PCR analysis of neural tissue from WNV RNA—positive horses demonstrated that the medulla contained the highest mean concentration of viral RNA and that WNV RNA could be detected in samples extracted from formalin-fixed neural tissue. A comparison of WNV RT-PCR amplification strategies found that nested RT-PCR improved diagnostic sensitivity only slightly over a single round of amplification and that a quantitative (TaqMan) assay had sensitivity and specificity that were equivalent to those of nested amplification.
Collapse
Affiliation(s)
- Steven B Kleiboeker
- Veterinary Medical Diagnostic Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA
| | | | | | | | | |
Collapse
|
14
|
Abstract
Mosquito-borne diseases affect horses worldwide. Mosquito-borne diseases generally cause encephalomyelitis in the horse and can be difficult to diagnose antemortem. In addition to general disease, and diagnostic and treatment aspects, this review article summarizes the latest information on these diseases, covering approximately the past 5 years, with a focus on new equine disease encroachments, diagnostic and vaccination aspects, and possible therapeutics on the horizon.
Collapse
|
15
|
Rocha PRD, Bertuglia A, Biasibetti E, Bullone M, Rosamilia A, Masoero L, Capucchio MT. Subependymal Reaction Secondary to Choroid Plexus Papilloma in a Horse. J Equine Vet Sci 2014. [DOI: 10.1016/j.jevs.2013.09.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
16
|
Williams JH, Mentoor JDL, Van Wilpe E, Venter M. Comparative pathology of neurovirulent lineage 1 (NY99/385) and lineage 2 (SPU93/01) West Nile virus infections in BALBc mice. Vet Pathol 2014; 52:140-51. [PMID: 24513801 DOI: 10.1177/0300985813520246] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The pathology in mice infected with neurovirulent South African lineage 2 West Nile virus (WNV) strains has not previously been described. Three- to 4-month-old male BALBc mice were infected with South African neurovirulent lineage 2 (SPU93/01) or lineage 1 (NY385/99) WNV strains and the gross and microscopic central nervous system (CNS) and extra-CNS pathology of both investigated and compared. Mice infected with both lineages showed similar illness, paralysis, and death from days 7 to 11 postinfection (PI). Two survivors of each lineage were euthanized on day 21 PI. WNV infection was confirmed by nested real-time reverse transcription polymerase chain reaction of tissues, mostly brain, in the majority of mice euthanized sick or that died and in 1 healthy lineage 2 survivor. Gross lesions caused by both lineages were identical and included marked gastric and proximal small intestinal fluid distension as described in a previous mouse study, but intestinal microscopic lesions differed. CNS lesions were subtle. Immunohistochemical (IHC)-positive labeling for WNV E protein was found in neurons multifocally in the brain of 3 lineage 1-infected and 3 lineage 2-infected mice from days 9 to 11 PI, 4 of these including brainstem neurons, and of cecal myenteric ganglion neurons in 1 lineage 2-infected day 8 PI mouse. Findings supported hypotheses in hamsters that gastrointestinal lesions are likely of brainstem origin. Ultrastructurally, virus-associated cytoplasmic vesicular or crystalline structures, or amorphous structures, were found to label IHC positive in control-positive avian cardiomyocytes and mouse thalamic neurons, respectively, and WNV-like 50-nm particles, which were scarce, did not label.
Collapse
Affiliation(s)
- J H Williams
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Republic of South Africa Department of Medical Virology, Faculty of Health Sciences, University of Pretoria, Republic of South Africa
| | - J D L Mentoor
- Department of Medical Virology, Faculty of Health Sciences, University of Pretoria, Republic of South Africa
| | - E Van Wilpe
- Electron Microscopy Unit, Department of Anatomy, Faculty of Veterinary Science, University of Pretoria, Republic of South Africa
| | - M Venter
- Department of Medical Virology, Faculty of Health Sciences, University of Pretoria, Republic of South Africa Center for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, Sandringham, Johannesburg, Republic of South Africa
| |
Collapse
|
17
|
Abutarbush SM, Al-Majali AM. West Nile Virus Infection in Horses in Jordan: Clinical Cases, Seroprevalence and Risk Factors. Transbound Emerg Dis 2014; 61 Suppl 1:1-6. [DOI: 10.1111/tbed.12191] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2013] [Indexed: 11/30/2022]
Affiliation(s)
- S. M. Abutarbush
- Department of Veterinary Clinical Sciences; Faculty of Veterinary Medicine; Jordan University of Science and Technology; Irbid Jordan
| | - A. M. Al-Majali
- Department of Veterinary Clinical Sciences; Faculty of Veterinary Medicine; Jordan University of Science and Technology; Irbid Jordan
| |
Collapse
|
18
|
Tee SY, Horadagoda N, Mogg TD. Kunjin flaviviral encephalomyelitis in an Arabian gelding in New South Wales, Australia. Aust Vet J 2012; 90:321-4. [PMID: 22827627 DOI: 10.1111/j.1751-0813.2012.00951.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/26/2011] [Indexed: 11/29/2022]
Abstract
Flaviviruses, including Kunjin virus, are arboviruses that cause encephalomyelitis in humans and horses. This case report describes an Arabian gelding exhibiting neurological signs of flavivirus encephalomyelitis, the diagnostic investigation and confirmation of an unreported case of Kunjin virus equine encephalomyelitis in Australia.
Collapse
Affiliation(s)
- S Y Tee
- University Veterinary Teaching Centre Camden, 410 Werombi Rd, Camden, NSW 2570, Australia.
| | | | | |
Collapse
|
19
|
Venter M, Human S, van Niekerk S, Williams J, van Eeden C, Freeman F. Fatal neurologic disease and abortion in mare infected with lineage 1 West Nile virus, South Africa. Emerg Infect Dis 2011; 17:1534-6. [PMID: 21801644 PMCID: PMC3381566 DOI: 10.3201/eid1708.101794] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
In 2010, lineage 1 West Nile virus was detected in South Africa in the brain of a pregnant mare that succumbed to neurologic disease and in her aborted fetus, suggesting an association with abortion in horses. All West Nile virus strains previously detected in horses and humans in South Africa were lineage 2.
Collapse
|
20
|
Ward MP. Equine West Nile virus disease occurrence and the Normalized Difference Vegetation Index. Prev Vet Med 2008; 88:205-12. [PMID: 19054585 DOI: 10.1016/j.prevetmed.2008.10.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Revised: 09/10/2008] [Accepted: 10/15/2008] [Indexed: 10/21/2022]
Abstract
The association between the Normalized Difference Vegetation Index (NDVI) and periods of above- or below-average reported cases of equine West Nile virus encephalomyelitis, reported in Texas between 2002 and 2004, was investigated. A time-series of case reports, using a biweekly window, was constructed. Because of the disparity in number of cases reported (1698, 672 and 101 in 2002, 2003 and 2004, respectively), data were standardized by calculating the number of cases reported during each biweekly period as a ratio of the annual average number of cases reported. The mean NDVI (0.439) in Texas in biweekly periods in which cases were reported was significantly higher (P<0.001) than the mean NDVI (0.396) in periods in which cases were not reported. The best-fitting model of standardized case ratios included the mean NDVI in the preceding 4-week period. This association was further investigated in the two ecological regions of Texas in which most cases were reported during the study period--Prairies and Lakes, and the Panhandle Plains. Standardized case ratios in the Prairies and Lakes ecoregion were best predicted by NDVI estimated 19-20 weeks previously, whereas standardized case ratios in the Panhandle Plains region were most strongly associated with NDVI estimated 1-4 weeks previously, indicating that the temporal lag between appropriate environmental conditions and resulting increased risk of WNV transmission can vary in different regions. The associations identified could be useful in an early-warning system of increased disease risk.
Collapse
Affiliation(s)
- Michael P Ward
- Department of Veterinary Integrative Biosciences, MS 4458, Texas A&M University, College Station, TX 77843-4458, USA.
| |
Collapse
|
21
|
Leblond A, Hendrikx P, Sabatier P. West Nile Virus Outbreak Detection Using Syndromic Monitoring in Horses. Vector Borne Zoonotic Dis 2007; 7:403-10. [PMID: 17767410 DOI: 10.1089/vbz.2006.0593] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Recent outbreaks of West Nile virus-associated (WNV) diseases, both in the old World and Americas, underline the importance for early warning systems that rapidly identify emerging and re-emerging diseases and thus help in their control. Traditional approaches of disease monitoring become less reliable and increasingly costly when used for rare health-related events, such as WNV outbreaks in southern France. The objective of this work was to discuss methodological issues related to syndromic monitoring of WNV-associated disease in Camargue horses by veterinary practitioners. Tracking cases of equine encephalitis by veterinarians is an example of such syndromic monitoring of an emerging disease. Signs of illness, observed prior diagnostic confirmation, can be of interest because they may provide an early warning for WNV circulation in a given area and allow authorities to take appropriate preventive measures for public health.
Collapse
Affiliation(s)
- A Leblond
- UMR CNRS 5525 TIMC, Unit Environnement et Prévisions de la Santé des Populations, Ecole Nationale Vétérinaire de Lyon, Université de Lyon, Marcy l'Etoile, Lyon, France.
| | | | | |
Collapse
|
22
|
Gardner IA, Wong SJ, Ferraro GL, Balasuriya UB, Hullinger PJ, Wilson WD, Shi PY, MacLachlan NJ. Incidence and effects of West Nile virus infection in vaccinated and unvaccinated horses in California. Vet Res 2007; 38:109-16. [PMID: 17274156 DOI: 10.1051/vetres:2006045] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A prospective cohort study was used to estimate the incidence of West Nile virus (WNV) infection in a group of unvaccinated horses (n = 37) in California and compare the effects of natural WNV infection in these unvaccinated horses to a group of co-mingled vaccinated horses (n = 155). Horses initially were vaccinated with either inactivated whole virus (n = 87) or canarypox recombinant (n = 68) WNV vaccines during 2003 or 2004, prior to emergence of WNV in the region. Unvaccinated horses were serologically tested for antibodies to WNV by microsphere immunoassay incorporating recombinant WNV E protein (rE MIA) in December 2003, December 2004, and every two months thereafter until November 2005. Clinical neurologic disease attributable to WNV infection (West Nile disease (WND)) developed in 2 (5.4%) of 37 unvaccinated horses and in 0 of 155 vaccinated horses. One affected horse died. Twenty one (67.7%) of 31 unvaccinated horses that were seronegative to WNV in December, 2004 seroconverted to WNV before the end of the study in November, 2005. Findings from the study indicate that currently-available commercial vaccines are effective in preventing WND and their use is financially justified because clinical disease only occurred in unvaccinated horses and the mean cost of each clinical case of WND was approximately 45 times the cost of a 2-dose WNV vaccination program.
Collapse
Affiliation(s)
- Ian A Gardner
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Sánchez MD, Pierson TC, Degrace MM, Mattei LM, Hanna SL, Del Piero F, Doms RW. The neutralizing antibody response against West Nile virus in naturally infected horses. Virology 2006; 359:336-48. [PMID: 17055550 DOI: 10.1016/j.virol.2006.08.047] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Revised: 07/21/2006] [Accepted: 08/29/2006] [Indexed: 11/22/2022]
Abstract
A major neutralizing epitope (here referred to as the T332 epitope) located on the lateral surface of domain III (DIII) of the West Nile virus (WNV) envelope protein has been identified based on the analysis of murine monoclonal antibodies. However, little is known about the humoral immune response against WNV in a natural host or whether DIII in general or the T332 epitope in particular are important targets of neutralizing antibodies in vivo. To characterize the types of antibodies produced during infection with WNV, we studied a group of naturally infected horses. Using immune adsorption assays coupled with the use of virus particles bearing mutations in the T332 epitope, we found that in some animals neutralizing activity against DIII and the T332 epitope was below the limit of detection. In contrast, some animals generated a significant fraction of neutralizing activity to DIII and the T332 epitope. Thus, while antibodies to the T332 epitope did not represent a significant fraction of the total antibody response in the infected animals studied, in some horses, they comprised a significant fraction of neutralizing activity, making this an important but far from dominant neutralizing epitope. Rather, the neutralizing response to WNV generated in infected horses is both variable and polyclonal in nature, with epitopes within and outside of DIII playing important roles.
Collapse
Affiliation(s)
- Melissa D Sánchez
- Department of Microbiology, University of Pennsylvania, 225 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104, USA
| | | | | | | | | | | | | |
Collapse
|
24
|
Pellegrini-Masini A, Livesey LC. Meningitis and Encephalomyelitis in Horses. Vet Clin North Am Equine Pract 2006; 22:553-89, x. [PMID: 16882487 DOI: 10.1016/j.cveq.2006.03.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
This article provides an overview of meningitis and encephalomyelitis in horses, including diagnostic tests, treatment developments, and preventative measures reported in the equine and human medical literature of the past few years.
Collapse
Affiliation(s)
- Alessandra Pellegrini-Masini
- Equine Section, Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA.
| | | |
Collapse
|
25
|
Ward MP, Ramsay BH, Gallo K. Rural cases of equine West Nile virus encephalomyelitis and the normalized difference vegetation index. Vector Borne Zoonotic Dis 2005; 5:181-8. [PMID: 16011435 DOI: 10.1089/vbz.2005.5.181] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Data from an outbreak (August to October, 2002) of West Nile virus (WNV) encephalomyelitis in a population of horses located in northern Indiana was scanned for clusters in time and space. One significant (p = 0.04) cluster of case premises was detected, occurring between September 4 and 10 in the south-west part of the study area (85.70 degrees N, 45.50 degrees W). It included 10 case premises (3.67 case premises expected) within a radius of 2264 m. Image data were acquired by the Advanced Very High Resolution Radiometer (AVHRR) sensor onboard a National Oceanic and Atmospheric Administration polar-orbiting satellite. The Normalized Difference Vegetation Index (NDVI) was calculated from visible and near-infrared data of daily observations, which were composited to produce a weekly-1km(2) resolution raster image product. During the epidemic, a significant (p < 0.01) decrease (0.025 per week) in estimated NDVI was observed at all case and control premise sites. The median estimated NDVI (0.659) for case premises within the cluster identified was significantly (p < 0.01) greater than the median estimated NDVI for other case (0.571) and control (0.596) premises during the same period. The difference in median estimated NDVI for case premises within this cluster, compared to cases not included in this cluster, was greatest (5.3% and 5.1%, respectively) at 1 and 5 weeks preceding occurrence of the cluster. The NDVI may be useful for identifying foci of WNV transmission.
Collapse
Affiliation(s)
- Michael P Ward
- Department of Veterinary Pathobiology, Purdue University School of Veterinary Medicine, West Lafayette, Indiana, USA.
| | | | | |
Collapse
|
26
|
Salazar P, Traub-Dargatz JL, Morley PS, Wilmot DD, Steffen DJ, Cunningham WE, Salman MD. Outcome of equids with clinical signs of West Nile virus infection and factors associated with death. J Am Vet Med Assoc 2004; 225:267-74. [PMID: 15323385 DOI: 10.2460/javma.2004.225.267] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine outcome of equids in the western United States with clinical signs of West Nile virus (WNV) infection and identify factors associated with risk of death in infected equids. DESIGN Cross-sectional study. ANIMALS 484 equids in Nebraska and Colorado. PROCEDURE Owners of 484 equids with laboratory-confirmed West Nile virus infection in Nebraska and Colorado were contacted by telephone, and a questionnaire was used to obtain information on signalment, management, clinical signs, date of disease onset, duration of disease, WNV vaccination status, and health status at the time of the interview. RESULTS 137 of 482 (28.4%) animals died or were euthanatized. Ataxia, lethargy, muscle fasciculations, and weakness were the most common clinical signs of disease. Animals > or = 3 years old were more likely to die than were animals < or = 2 years old. Unvaccinated equids were twice as likely to die as were animals that had been vaccinated at least once prior to the onset of disease. Animals that were recumbent and unable to rise were 78 times as likely to die as were animals that never lost the ability to rise. Females were 2.9 times as likely to die as males. Two hundred seventy-one of 339 (79.9%) animals that survived recovered fully; mean duration of disease for these animals was 22.3 days. CONCLUSIONS AND CLINICAL RELEVANCE Among equids with WNV infection, age, vaccination status, an inability to rise, and sex were associated with the risk of death.
Collapse
Affiliation(s)
- Patricia Salazar
- Animal Population Health Institute, Colorado State University, Fort Collins, CO 80523, USA
| | | | | | | | | | | | | |
Collapse
|
27
|
Porter MB, Long M, Gosche DG, II HMS, Hines MT, Rossano M, Sellon DC. Immunoglobulin M-Capture Enzyme-Linked Immunosorbent Assay Testing of Cerebrospinal Fluid and Serum from Horses Exposed to West Nile Virus by Vaccination or Natural Infection. J Vet Intern Med 2004. [DOI: 10.1111/j.1939-1676.2004.tb02634.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
28
|
Schuler LA, Khaitsa ML, Dyer NW, Stoltenow CL. Evaluation of an outbreak of West Nile virus infection in horses: 569 cases (2002). J Am Vet Med Assoc 2004; 225:1084-9. [PMID: 15515988 DOI: 10.2460/javma.2004.225.1084] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To characterize an outbreak of West Nile virus (WNV) infection in horses in North Dakota in 2002, evaluate vaccine effectiveness, and determine horse characteristics and clinical signs associated with infection. DESIGN Retrospective study. ANIMALS 569 horses. PROCEDURE Data were obtained from veterinary laboratory records, and a questionnaire was mailed to veterinarians of affected horses. RESULTS Affected horses were defined as horses with typical clinical signs and seroconversion or positive results of virus isolation; affected horses were detected in 52 of the 53 counties and concentrated in the eastern and northeastern regions of the state. Among affected horses, 27% (n = 152) were vaccinated against WNV, 54% (309) were not, and 19% (108) had unknown vaccination status; 61 % (345) recovered, 22% (126) died, and 17% (98) had unknown outcome. The odds of death among nonvaccinated horses were 3 and 16 times the odds among horses that received only 1 or 2 doses of vaccine and horses that were vaccinated according to manufacturer's recommendations, respectively. Horses with recumbency, caudal paresis, and age > 5 years had higher odds of death, whereas horses with incoordination had lower odds of death, compared with affected horses without these characteristics. CONCLUSIONS AND CLINICAL RELEVANCE Vaccination appears to have beneficial effects regarding infection and death caused by WNV.
Collapse
Affiliation(s)
- Larry A Schuler
- North Dakota State Board of Animal Health, 600 E Boulevard Ave, Dept 602, Bismarck, ND 58505-0020, USA
| | | | | | | |
Collapse
|
29
|
Morrey JD, Day CW, Julander JG, Olsen AL, Sidwell RW, Cheney CD, Blatt LM. Modeling hamsters for evaluating West Nile virus therapies. Antiviral Res 2004; 63:41-50. [PMID: 15196819 DOI: 10.1016/j.antiviral.2004.02.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2003] [Accepted: 02/23/2004] [Indexed: 10/26/2022]
Abstract
A hamster model infected with a New York crow brain isolate of West Nile virus (WNV) was characterized for evaluating potential antiviral therapies. Older hamsters (7-11 weeks old) had a lower mortality of approximately 50% and more apparent disease signs as compared to >90% mortality in younger hamsters and mice. Disease signs such as limb strength, lacrimation, front limb tremors, somnolence, and deficiencies in neurological responses were noted at different times after viral injection. Weight loss was a marker for WNV disease signs, whereas, the ability to climb up an inclined ramp was associated with whether the animals survived the disease or died. Infectious WNV assays performed on tissues from hamsters during development of the infection indicated that viral titers peaked first in plasma, but that titers were eventually highest in kidney tissue. Viral titers achieved maximal levels in brain tissue on 6 dpi, which was 1-2 days before strong neurological signs and death started to occur. Maximal spleen and plasma titers were achieved sooner in young hamsters as compared with older hamsters, which correlated with increased susceptibility. To test the hypothesis that older hamsters would be more sensitive for identifying antiviral effects, Infergen, a consensus human interferon-alpha highly active against WNV in cell culture, was administered subcutaneously to older and younger hamsters beginning on 2 dpi. The effects of Infergen on weight change, survival, and climbing ability of infected animals were more apparent in older hamsters than in younger hamsters. The use of older hamsters is another WNV-infectious model, in addition to mice, for evaluating potential antiviral therapies.
Collapse
Affiliation(s)
- John D Morrey
- Department of Animal, Dairy, and Veterinary Sciences, Institute for Antiviral Research, Biotechnology Center, Utah State University, 4700 Old Main Hill, Room 305, Logan, UT 84322-4700, USA.
| | | | | | | | | | | | | |
Collapse
|
30
|
Tewari D, Kim H, Feria W, Russo B, Acland H. Detection of West Nile virus using formalin fixed paraffin embedded tissues in crows and horses: quantification of viral transcripts by real-time RT-PCR. J Clin Virol 2004; 30:320-5. [PMID: 15163421 DOI: 10.1016/j.jcv.2004.01.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 01/05/2004] [Accepted: 01/16/2004] [Indexed: 10/26/2022]
Abstract
West Nile virus (WNV) RNA was quantified in WNV infected crows and horses with the help of a real-time reverse transcriptase-PCR assay. A 5' nuclease assay, based on NS5 gene detection with a fluorescent probe was used for quantifying WNV RNA using formalin fixed paraffin embedded tissue specimens. Quantitative detection of WNV RNA showed the presence of a higher amount of the viral RNA in crow tissues compared to equine tissues and these results correlated well with the detection of WNV antigen by immunostaining. In crows, the highest amount of virus was seen in the intestine and in horses in the brain.
Collapse
Affiliation(s)
- Deepanker Tewari
- Pennsylvania Veterinary Laboratory, 2305 N Cameron St, Harrisburg, PA 17110, USA.
| | | | | | | | | |
Collapse
|
31
|
Ward MP, Levy M, Thacker HL, Ash M, Norman SKL, Moore GE, Webb PW. Investigation of an outbreak of encephalomyelitis caused by West Nile virus in 136 horses. J Am Vet Med Assoc 2004; 225:84-9. [PMID: 15239478 DOI: 10.2460/javma.2004.225.84] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To describe an outbreak of encephalomyelitis caused by West Nile virus (WNV) in horses in northern Indiana. DESIGN Case series. ANIMALS 170 horses. PROCEDURES Horses with clinical signs suggestive of encephalomyelitis caused by WNV were examined. Date, age, sex, breed, and survival status were recorded. Serum samples were tested for anti-WNV antibodies, and virus isolation was attempted from samples of brain tissue. Climate data from local weather recording stations were collected. An epidemic curve was constructed, and case fatality rate was calculated. RESULTS The most common clinical signs were ataxia, hind limb paresis, and muscle tremors and fasciculations. Eight horses had been vaccinated against WNV from 2 to 21 days prior to the appearance of clinical signs. West Nile virus was isolated from brain tissue of 2 nonvaccinated horses, and anti-WNV IgM antibodies were detected in 132 nonvaccinated horses; in 2 other nonvaccinated horses, anti-WNV antibodies were detected and WNV was also isolated from brain tissue. Thirty-one (22.8%) horses died or were euthanatized. The peak of the outbreak occurred on September 6, 2002. Ambient temperatures were significantly lower after the peak of the outbreak, compared with prior to the peak. CONCLUSIONS AND CLINICAL RELEVANCE The peak risk period for encephalomyelitis caused by WNV in northern Indiana was mid-August to mid-September. Reduction in cases coincided with decreasing ambient temperatures. Because of a substantial case fatality rate, owners of horses in northern Indiana should have their horses fully protected by vaccination against WNV before June. In other regions of the United States with a defined mosquito breeding season, vaccination of previously nonvaccinated horses should commence at least 4 months before the anticipated peak in seasonal mosquito numbers, and for previously vaccinated horses, vaccine should be administered no later than 2 months before this time.
Collapse
Affiliation(s)
- Michael P Ward
- Department of Veterinary Pathobiology, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907-2027, USA
| | | | | | | | | | | | | |
Collapse
|
32
|
|
33
|
Porter MB, Long MT, Getman LM, Giguère S, MacKay RJ, Lester GD, Alleman AR, Wamsley HL, Franklin RP, Jacks S, Buergelt CD, Detrisac CJ. West Nile virus encephalomyelitis in horses: 46 cases (2001). J Am Vet Med Assoc 2003; 222:1241-7. [PMID: 12725313 DOI: 10.2460/javma.2003.222.1241] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine signalment, clinical findings, results of diagnostic testing, outcome, and postmortem findings in horses with West Nile virus (WNV) encephalomyelitis. DESIGN Retrospective study. ANIMALS 46 horses with WNV encephalomyelitis. PROCEDURE Clinical data were extracted from medical records of affected horses. RESULTS On the basis of clinical signs and results of serologic testing, WNV encephalomyelitis was diagnosed in 46 of 56 horses with CNS signs. Significantly more males than females were affected. Increased rectal temperature, weakness or ataxia, and muscle fasciculations were the most common clinical signs. Paresis was more common than ataxia, although both could be asymmetrical and multifocal. Supportive treatment included anti-inflammatory medications, fluids, antimicrobials, and slinging of recumbent horses. Results of the IgM capture ELISA and the plaque reduction neutralization test provided a diagnosis in 43 horses, and only results of the plaque reduction neutralization test were positive in 3 horses. Mortality rate was 30%, and 71% of recumbent horses were euthanatized. One horse that had received 2 vaccinations for WNV developed the disease and was euthanatized. Follow-up communications with 19 owners revealed that most horses had residual deficits at 1 month after release from the hospital; abnormalities were resolved in all but 2 horses by 12 months after release. CONCLUSIONS AND CLINICAL RELEVANCE Our findings were similar to those of previous WNV outbreaks in horses but provided additional clinical details from monitored hospitalized horses. Diagnostic testing is essential to diagnosis, treatment is supportive, and recovery rate of discharged ambulatory horses is < 100%.
Collapse
Affiliation(s)
- Michael B Porter
- Department of Large Animal Clinical Sciences , College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Wang T, Magnarelli LA, Anderson JF, Gould LH, Bushmich SL, Wong SJ, Fikrig E. A recombinant envelope protein-based enzyme-linked immunosorbent assay for West Nile virus serodiagnosis. Vector Borne Zoonotic Dis 2003; 2:105-9. [PMID: 12653304 DOI: 10.1089/153036602321131904] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Recombinant West Nile virus envelope (E) protein was examined in enzyme-linked immunosorbent assay (ELISA) to detect antibodies elicited during West Nile virus infection. Horses (nine of 10) and humans (six of six) with confirmed West Nile virus infection had IgG and/or IgM antibodies to the E protein. Antibodies to the recombinant West Nile virus membrane and nonstructural 1 proteins were not detected in any of these sera. An E protein-based ELISA may aid in the serological diagnosis of West Nile virus infection.
Collapse
Affiliation(s)
- Tian Wang
- Section of Rheumatology, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520-8031, USA
| | | | | | | | | | | | | |
Collapse
|
35
|
Wamsley HL, Alleman AR, Porter MB, Long MT. Findings in cerebrospinal fluids of horses infected with West Nile virus: 30 cases (2001). J Am Vet Med Assoc 2002; 221:1303-5. [PMID: 12418697 DOI: 10.2460/javma.2002.221.1303] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate CSF in horses with confirmed West Nile virus encephalomyelitis. DESIGN Retrospective study. ANIMALS 30 horses. PROCEDURE Results of CSF analyses from horses with acute neurologic signs attributed to West Nile virus infection that was confirmed by immunoglobulin M antibody capture ELISA were reviewed and analyzed. RESULTS Among 30 CSF samples, findings in 8 (27%) were within reference ranges and in 22 (73%) were abnormal. Among the 22 abnormal samples, mononuclear pleocytosis was found in 16 (73%) and high protein concentration with nucleated cell count within reference range was found in 6 (27%) samples. A predominance of lymphocytes was found in 11 of 16 samples with mononuclear pleocytosis, and a predominance of large mononuclear cells was found in 5 of 16 samples. Sensitivities of analyses of CSF obtained from the lumbosacral and atlanto-occipital regions of the spinal cord were 89 and 50%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Results suggest that in horses with acute onset of neurologic signs caused by West Nile virus encephalomyelitis, findings in the CSF are likely to be abnormal, mononuclear pleocytosis with lymphocytic predominance may be most commonly observed, and CSF collected from the lumbosacral region may be abnormal more commonly than CSF collected from the atlanto-occipital region.
Collapse
Affiliation(s)
- Heather L Wamsley
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32610, USA
| | | | | | | |
Collapse
|
36
|
Hall RA, Broom AK, Smith DW, Mackenzie JS. The ecology and epidemiology of Kunjin virus. Curr Top Microbiol Immunol 2002; 267:253-69. [PMID: 12082993 DOI: 10.1007/978-3-642-59403-8_13] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Affiliation(s)
- R A Hall
- Department of Microbiology and Parasitology, School of Molecular and Microbial Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | | | | | | |
Collapse
|
37
|
Abstract
WN virus is one of the most ubiquitous arboviruses occurring over a broad geographical range and in a wide diversity of vertebrate host and vector species. The virus appears to be maintained in endemic foci on the African continent and is transported annually to temperate climates to the north in Europe and to the south in South Africa. Reports of clinical disease due to natural WN virus infection in wild or domestic animals were much less common than reports of infection (virus isolation or antibody detection). Until recently, records of morbidity and mortality in wild birds were confined to a small number of cases and infections causing encephalitis, sometimes fatal, in horses were reported infrequently. In the period 1996-2001, there was an increase in outbreaks of illness due to WN virus in animals as well as humans. Within the traditional range of WN virus, encephalitis was reported in horses in Italy in 1998 and in France in 2000. The first report of disease and deaths caused by WN virus infection in domestic birds was reported in Israel in 1997-1999, involving hundreds of young geese. In 1999 WN virus reached North America and caused an outbreak of encephalitis in humans in the New York area at the same time as a number of cases of equine encephalitis and deaths in American crows and a variety of other bird species, both North American natives and exotics. Multi-state surveillance for WN virus has been in place since April 2000 and has resulted in the detection of WN virus in thousands of dead birds from an increasing number of species in North America, and also in several species of mammals. The surveillance system that has developed in North America because of the utility of testing dead birds for the rapid detection of WN virus presence has been a unique integration of public health and wildlife health agencies. It has been suggested that the recent upsurge in clinical WN virus infection in wild and domestic animals as well as in humans may be related to the emergence of one or more new strains of WN virus. Virus isolated in New York in 1999 was found to be identical to that from Israel. It was alarming for WN virus to so easily invade the United States and surprising that it became established so quickly in the temperature climate of New York. Its persistence and rapid expansion in the United States leave a number of unanswered questions. New disease characteristics and patterns have occurred and more are evolving as WN virus further invades the western hemisphere. Additional animal research is needed to answer these questions. Some of the research needs include bird migration as a mechanism of virus dispersal, vector and vertebrate host relationships, virus persistence mechanisms, laboratory diagnosis, viral pathogenesis, risk factor studies, vaccine development, and WN virus impact on wildlife (CDC 2001a). Determination of the primary reservoir host species that are involved in the epidemiology of WN virus and the suitable sentinel species for active surveillance are also important research areas.
Collapse
Affiliation(s)
- R G McLean
- National Wildlife Health Center, United States Geological Survey, Madison, WI, USA
| | | | | | | |
Collapse
|
38
|
Steinman A, Banet C, Sutton GA, Yadin H, Hadar S, Brill A. Clinical signs of West Nile virus encephalomyelitis in horses during the outbreak in Israel in 2000. Vet Rec 2002; 151:47-9. [PMID: 12148602 DOI: 10.1136/vr.151.2.47] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Between August and October 2000, 76 horses were reported by veterinary practitioners as having signs of a neurological disorder, varying from an involvement of the spinal cord alone to the entire central nervous system; 15 of the horses died or were euthanased as a result of their grave prognosis or secondary complications. At the same time, an outbreak of West Nile virus infection affected people and birds, principally domestic geese. West Nile virus was isolated from four of the horses with encephalomyelitis and five other horses seroconverted, indicating that the virus was the probable cause of the outbreak in horses. Three of the cases from which the virus was isolated are described briefly and one case is described in detail. This horse behaved abnormally and had general proprioceptive deficits in all four limbs. Its neurological condition deteriorated after two days and severe inspiratory dyspnoea due to a failure to abduct the arytenoids necessitated a tracheostomy. It died on the fourth day and histological lesions were observed in the brain stem and grey matter of the spinal cord.
Collapse
Affiliation(s)
- A Steinman
- School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel
| | | | | | | | | | | |
Collapse
|