FREE SHIPPING over $40
OVER 10000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Viruses2022; 14(11); 2576; doi: 10.3390/v14112576

Epidemiological Aspects of Equid Herpesvirus-Associated Myeloencephalopathy (EHM) Outbreaks.

Abstract: Equid Herpesvirus Myeloencephalopathy (EHM) is a multifactorial disease following an EHV-1 infection in Equidae. We investigated a total of 589 horses on 13 premises in Europe in search of risk factors for the development of EHM. We found that fever ( < 0.001), increasing age ( = 0.032), and female sex ( = 0.042) were risk factors for EHM in a logistic mixed model. Some breeds had a decreased risk to develop EHM compared to others (Shetland and Welsh ponies; = 0.017; = 0.031), and fewer EHV-1-vaccinated horses were affected by EHM compared to unvaccinated horses ( = 0.02). Data evaluation was complex due to high variability between outbreaks with regards to construction and environment; viral characteristics and the virus's transmissibility were affected by operational management. This study confirms earlier suspected host-specific risk factors, and our data support the benefit of high vaccine coverage at high-traffic boarding facilities.
Get Full Text
Publication Date: 2022-11-21 PubMed ID: 36423188PubMed Central: PMC9695031DOI: 10.3390/v14112576Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
LinkedInCopy
  • Journal Article
  • Research Support
  • Non-U.S. Gov't

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research investigated risk factors for Equid Herpesvirus Myeloencephalopathy (EHM), a disease in horses, in an European context. They found fever, older age, female sex, and certain breeds to increase the risk, while vaccination seems to have a protective effect, and highlighted the variability of outbreaks due to different environmental and management factors.

Introduction to the Study

  • The study focuses on Equid Herpesvirus Myeloencephalopathy (EHM), a disease that affects members of the Equidae family (including horses) and is associated with the Equid Herpesvirus-1 (EHV-1) infection.
  • The researchers aimed to investigate potential risk factors that could contribute to the development of EHM by examining a large sample—589 horses across 13 premises in Europe.

Findings and Results

  • The results indicated that fever, increasing age, and female sex were significant risk factors for EHM. In other words, horses that had a fever, were older, or were female, had higher chances of developing EHM.
  • Interestingly, the study found a different level of susceptibility among different horse breeds – specifically, Shetland and Welsh ponies were found to have a decreased risk of developing EHM compared to other breeds.
  • The research also highlighted the protective effect of EHV-1 vaccination since fewer vaccinated horses developed EHM than their unvaccinated counterparts.
  • However, the interpretation of data was complicated due to the high variability between different outbreaks. This variability was linked to factors such as the construction and environment of the premises, characteristics of the virus, and how the premises were managed operationally.

Conclusion and Implications

  • This study not only confirmed some of the previously suspected risk factors associated with EHM but also provided new evidence supporting the benefit of EHV-1 vaccination.
  • Specifically, the findings suggest that implementing high vaccine coverage in high-traffic boarding facilities could significantly help in controlling EHM epidemics.
  • The study also underscores the need for further research to better understand the multifactorial nature of EHM, as well as the influence of different environmental and management factors on the disease’s spread and severity.

Cite This Article

APA
Klouth E, Zablotski Y, Petersen JL, de Bruijn M, Gröndahl G, Müller S, Goehring LS. (2022). Epidemiological Aspects of Equid Herpesvirus-Associated Myeloencephalopathy (EHM) Outbreaks. Viruses, 14(11), 2576. https://doi.org/10.3390/v14112576

Publication

Viruses
ISSN: 1999-4915
NlmUniqueID: 101509722
Country: Switzerland
Language: English
Volume: 14
Issue: 11
PII: 2576

Researcher Affiliations

Klouth, Eva
  • Center for Clinical Veterinary Medicine, Faculty of Veterinary Medicine, Ludwig-Maximilians University, 80539 Munich, Germany.
Zablotski, Yury
  • Center for Clinical Veterinary Medicine, Faculty of Veterinary Medicine, Ludwig-Maximilians University, 80539 Munich, Germany.
Petersen, Jessica L
  • Department of Animal Science, University of Nebraska, Lincoln, NE 68588, USA.
de Bruijn, Marco
  • Wolvega Equine Hospital, 8474 EA Oldeholtpade, The Netherlands.
Gröndahl, Gittan
  • National Veterinary Institute (SVE), 75189 Uppsala, Sweden.
Müller, Susanne
  • Baden-Wuerttemberg Animal Health Services, 70736 Fellbach, Germany.
Goehring, Lutz S
  • M.H. Gluck Equine Research Center, College of Agriculture, Food and the Environment, University of Kentucky, Lexington, KY 40506, USA.

MeSH Terms

  • Horses
  • Female
  • Animals
  • Herpesviridae Infections / epidemiology
  • Herpesviridae Infections / veterinary
  • Horse Diseases / epidemiology
  • Herpesvirus 1, Equid
  • Disease Outbreaks / veterinary
  • Risk Factors

Conflict of Interest Statement

The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.

References

This article includes 29 references
  1. Lunn DP, Davis-Poynter N, Flaminio MJ, Horohov DW, Osterrieder K, Pusterla N, Townsend HG. Equine herpesvirus-1 consensus statement.. J Vet Intern Med 2009 May-Jun;23(3):450-61.
    doi: 10.1111/j.1939-1676.2009.0304.xpubmed: 19645832google scholar: lookup
  2. Wilsterman S, Soboll-Hussey G, Lunn DP, Ashton LV, Callan RJ, Hussey SB, Rao S, Goehring LS. Equine herpesvirus-1 infected peripheral blood mononuclear cell subpopulations during viremia.. Vet Microbiol 2011 Apr 21;149(1-2):40-7.
    doi: 10.1016/j.vetmic.2010.10.004pubmed: 21093993google scholar: lookup
  3. Edington N, Welch HM, Griffiths L. The prevalence of latent Equid herpesviruses in the tissues of 40 abattoir horses.. Equine Vet J 1994 Mar;26(2):140-2.
    doi: 10.1111/j.2042-3306.1994.tb04353.xpubmed: 8575377google scholar: lookup
  4. Allen GP, Kydd JH, Slater JD, Smith KC. Advances in understanding of the pathogenesis, epidemiology and immunological control of equine herpesvirus abortion.. Equine Infectious Diseases VIII ed. R&W Publications; Newmarket, Suffolk, UK: 1999. pp. 129–146.
  5. Maxwell LK, Bentz BG, Gilliam LL, Ritchey JW, Pusterla N, Eberle R, Holbrook TC, McFarlane D, Rezabek GB, Meinkoth J, Whitfield C, Goad CL, Allen GP. Efficacy of the early administration of valacyclovir hydrochloride for the treatment of neuropathogenic equine herpesvirus type-1 infection in horses.. Am J Vet Res 2017 Oct;78(10):1126-1139.
    doi: 10.2460/ajvr.78.10.1126pmc: PMC6440545pubmed: 28945127google scholar: lookup
  6. Giessler K, Goehring L, Jacobs S, McCauley A, Esser M, Lee Y, Zarski L, Weber P, Soboll Hussey G. Use of the old horse model to identify horst factors contributing to EHM pathogenesis. Proceedings of the Conference of Research Workers in Animal Diseases Chicago, IL, USA. 4–7 December 2020; p. 269.
  7. van Maanen C, Sloet van Oldruitenborgh-Oosterbaan MM, Damen EA, Derksen AG. Neurological disease associated with EHV-1-infection in a riding school: clinical and virological characteristics.. Equine Vet J 2001 Mar;33(2):191-6.
    doi: 10.1111/j.2042-3306.2001.tb00600.xpubmed: 11266070google scholar: lookup
  8. Pusterla N, Hussey GS, Goehring LS. Equine Herpesvirus-1 Myeloencephalopathy.. Vet Clin North Am Equine Pract 2022 Aug;38(2):339-362.
    doi: 10.1016/j.cveq.2022.05.006pubmed: 35811201google scholar: lookup
  9. Goehring LS, van Winden SC, van Maanen C, Sloet van Oldruitenborgh-Oosterbaan MM. Equine herpesvirus type 1-associated myeloencephalopathy in The Netherlands: a four-year retrospective study (1999-2003).. J Vet Intern Med 2006 May-Jun;20(3):601-7.
    pubmed: 16734096doi: 10.1892/0891-6640(2006)20[601:ehtami]2.0.co;2google scholar: lookup
  10. Goehring LS, Wagner B, Bigbie R, Hussey SB, Rao S, Morley PS, Lunn DP. Control of EHV-1 viremia and nasal shedding by commercial vaccines.. Vaccine 2010 Jul 19;28(32):5203-11.
    doi: 10.1016/j.vaccine.2010.05.065pubmed: 20538091google scholar: lookup
  11. Nugent J, Birch-Machin I, Smith KC, Mumford JA, Swann Z, Newton JR, Bowden RJ, Allen GP, Davis-Poynter N. Analysis of equid herpesvirus 1 strain variation reveals a point mutation of the DNA polymerase strongly associated with neuropathogenic versus nonneuropathogenic disease outbreaks.. J Virol 2006 Apr;80(8):4047-60.
    doi: 10.1128/JVI.80.8.4047-4060.2006pmc: PMC1440451pubmed: 16571821google scholar: lookup
  12. Klouth E, Zablotski Y, Goehring LS. Apparent Breed Predilection for Equid Herpesvirus-1-Associated Myeloencephalopathy (EHM) in a Multiple-Breed Herd.. Pathogens 2021 Apr 29;10(5).
    doi: 10.3390/pathogens10050537pmc: PMC8145278pubmed: 33947126google scholar: lookup
  13. Allen GP. Risk factors for development of neurologic disease after experimental exposure to equine herpesvirus-1 in horses.. Am J Vet Res 2008 Dec;69(12):1595-600.
    doi: 10.2460/ajvr.69.12.1595pubmed: 19046006google scholar: lookup
  14. Traub-Dargatz JL, Pelzel-McCluskey AM, Creekmore LH, Geiser-Novotny S, Kasari TR, Wiedenheft AM, Bush EJ, Bjork KE. Case-control study of a multistate equine herpesvirus myeloencephalopathy outbreak.. J Vet Intern Med 2013 Mar-Apr;27(2):339-46.
    doi: 10.1111/jvim.12051pubmed: 23398291google scholar: lookup
  15. Schnabel CL, Babasyan S, Rollins A, Freer H, Wimer CL, Perkins GA, Raza F, Osterrieder N, Wagner B. An Equine Herpesvirus Type 1 (EHV-1) Ab4 Open Reading Frame 2 Deletion Mutant Provides Immunity and Protection from EHV-1 Infection and Disease.. J Virol 2019 Nov 15;93(22).
    doi: 10.1128/JVI.01011-19pmc: PMC6819910pubmed: 31462575google scholar: lookup
  16. Henninger RW, Reed SM, Saville WJ, Allen GP, Hass GF, Kohn CW, Sofaly C. Outbreak of neurologic disease caused by equine herpesvirus-1 at a university equestrian center.. J Vet Intern Med 2007 Jan-Feb;21(1):157-65.
    doi: 10.1111/j.1939-1676.2007.tb02942.xpubmed: 17338164google scholar: lookup
  17. Couroucé A, Tessier C, Pomares R, Thévenot R, Marcillaud-Pitel C, Pronost S, Legrand L, Pitel PH. EHV-1 neurological outbreak during a show jumping competition: A clinical and epidemiological study. Proceedings of the 11th International Equine Infectious Diseases Conference virtual conference. 27 September–1 October 2021; p. 52.
  18. Walter J, Seeh C, Fey K, Bleul U, Osterrieder N. Clinical observations and management of a severe equine herpesvirus type 1 outbreak with abortion and encephalomyelitis.. Acta Vet Scand 2013 Mar 5;55(1):19.
    doi: 10.1186/1751-0147-55-19pmc: PMC3630004pubmed: 23497661google scholar: lookup
  19. Petersen JL, Mickelson JR, Cothran EG, Andersson LS, Axelsson J, Bailey E, Bannasch D, Binns MM, Borges AS, Brama P, da Câmara Machado A, Distl O, Felicetti M, Fox-Clipsham L, Graves KT, Guérin G, Haase B, Hasegawa T, Hemmann K, Hill EW, Leeb T, Lindgren G, Lohi H, Lopes MS, McGivney BA, Mikko S, Orr N, Penedo MC, Piercy RJ, Raekallio M, Rieder S, Røed KH, Silvestrelli M, Swinburne J, Tozaki T, Vaudin M, M Wade C, McCue ME. Genetic diversity in the modern horse illustrated from genome-wide SNP data.. PLoS One 2013;8(1):e54997.
    doi: 10.1371/journal.pone.0054997pmc: PMC3559798pubmed: 23383025google scholar: lookup
  20. Felicetti M, Lopes MS, Verini-Supplizi A, Machado Ada C, Silvestrelli M, Mendonça D, Distl O. Genetic diversity in the Maremmano horse and its relationship with other European horse breeds.. Anim Genet 2010 Dec;41 Suppl 2:53-5.
    doi: 10.1111/j.1365-2052.2010.02102.xpubmed: 21070276google scholar: lookup
  21. Funder DC, Ozer DJ. Evaluating effect size in psychological research: Sense and nonsense.. Adv. Methods Pract. Psychol. Sci. 2019;2:156–168.
    doi: 10.1177/2515245919847202google scholar: lookup
  22. Jeffreys H. The Theory of Probability.. OUP; Oxford, UK: 1998.
  23. Vandenberghe E, Boshuizen B, Delesalle CJG, Goehring LS, Groome KA, van Maanen K, de Bruijn CM. New Insights into the Management of an EHV-1 (Equine Hospital) Outbreak.. Viruses 2021 Jul 22;13(8).
    doi: 10.3390/v13081429pmc: PMC8402800pubmed: 34452295google scholar: lookup
  24. Pusterla N, Barnum S, Young A, Mendonsa E, Lee S, Hankin S, Brittner S, Finno CJ. Molecular Monitoring of EHV-1 in Silently Infected Performance Horses through Nasal and Environmental Sample Testing.. Pathogens 2022 Jun 24;11(7).
    doi: 10.3390/pathogens11070720pmc: PMC9317758pubmed: 35889966google scholar: lookup
  25. Friday PA, Scarratt WK, Elvinger F, Timoney PJ, Bonda A. Ataxia and paresis with equine herpesvirus type 1 infection in a herd of riding school horses.. J Vet Intern Med 2000 Mar-Apr;14(2):197-201.
    doi: 10.1111/j.1939-1676.2000.tb02236.xpubmed: 10772493google scholar: lookup
  26. Bürki F, Nowotny N, Hinaidy B, Pallan C. Die Ätiologie der Lipizzanerseuche in Piber 1983: Equine Herpesvirus 1.. Wien Tierärztl Mschr. 1984;71:312–320.
  27. Ahdy AM, Ahmed BM, Elgamal MA, Shaalan M, Farag IM, Mahfouz ER, Darwish HR, Sayed-Ahmed MZ, Shalaby MA, El-Sanousi AA. Detection of Equid Alphaherpesvirus 1 from Arabian Horses with different clinical presentations between 2016-2019 in Egypt.. J Equine Vet Sci 2022 Jul;114:103960.
    doi: 10.1016/j.jevs.2022.103960pubmed: 35430231google scholar: lookup
  28. Minke JM, Fischer L, Baudu P, Guigal PM, Sindle T, Mumford JA, Audonnet JC. Use of DNA and recombinant canarypox viral (ALVAC) vectors for equine herpes virus vaccination.. Vet Immunol Immunopathol 2006 May 15;111(1-2):47-57.
    doi: 10.1016/j.vetimm.2006.01.008pubmed: 16580075google scholar: lookup
  29. Allen GP, Breathnach CC. Quantification by real-time PCR of the magnitude and duration of leucocyte-associated viraemia in horses infected with neuropathogenic vs. non-neuropathogenic strains of EHV-1.. Equine Vet J 2006 May;38(3):252-7.
    doi: 10.2746/042516406776866453pubmed: 16706281google scholar: lookup

Citations

This article has been cited 8 times.
  1. Durán MC, Suazo M, Maturana A, Vargas MP, García A, Ahumada C, Pezoa A, Goehring LS, Lara F. First Equine Herpes Myeloencephalopathy (EHM) Outbreak in Chile. Animals (Basel) 2025 Aug 11;15(16).
    doi: 10.3390/ani15162344pubmed: 40867672google scholar: lookup
  2. de la Cuesta-Torrado M, Vitale V, Velloso Alvarez A, Neira-Egea P, Diss C, Cuervo-Arango J. The Effect of Vaccination Status on Total Lymphocyte Count in Horses Affected by Equine Herpes Virus-1 Myeloencephalopathy. Animals (Basel) 2025 Apr 1;15(7).
    doi: 10.3390/ani15071019pubmed: 40218411google scholar: lookup
  3. de la Cuesta-Torrado M, Velloso Alvarez A, Santiago-Llorente I, Armengou L, Nieto F, Ríos J, Cruz-López F, Jose-Cunilleras E. Risk Factors and Long-Term Outcomes in Horses After the 2021 Outbreak of Equine Herpesvirus 1 Myeloencephalopathy, Valencia, Spain. J Vet Intern Med 2025 Mar-Apr;39(2):e70040.
    doi: 10.1111/jvim.70040pubmed: 40055829google scholar: lookup
  4. de la Cuesta-Torrado M, Velloso Alvarez A, Cárdenas-Rebollo JM, Neira-Egea P, Vitale V, Cuervo-Arango J. Comparison of clinical variables and outcome of 2 natural equine herpesvirus myeloencephalopathy outbreaks induced by equine herpesvirus-1 A2254/N752 strain in sport horses. J Vet Intern Med 2025 Jan-Feb;39(1):e17287.
    doi: 10.1111/jvim.17287pubmed: 39778904google scholar: lookup
  5. Pusterla N, Lawton K, Barnum S, Ross K, Purcell K. Investigation of an Outbreak of Equine Herpesvirus-1 Myeloencephalopathy in a Population of Aged Working Equids. Viruses 2024 Dec 21;16(12).
    doi: 10.3390/v16121963pubmed: 39772269google scholar: lookup
  6. Khan A, Olajide E, Friedrich M, Holt A, Goehring LS. Evaluation of Non-Invasive Sampling Techniques for the Molecular Surveillance of Equid Herpesviruses in Yearling Horses. Viruses 2024 Jul 7;16(7).
    doi: 10.3390/v16071091pubmed: 39066254google scholar: lookup
  7. Giessler KS, Goehring LS, Jacob SI, Davis A, Esser MM, Lee Y, Zarski LM, Weber PSD, Hussey GS. Impact of the host immune response on the development of equine herpesvirus myeloencephalopathy in horses. J Gen Virol 2024 May;105(5).
    doi: 10.1099/jgv.0.001987pubmed: 38767608google scholar: lookup
  8. Lunn DP, Burgess BA, Dorman DC, Goehring LS, Gross P, Osterrieder K, Pusterla N, Soboll Hussey G. Updated ACVIM consensus statement on equine herpesvirus-1. J Vet Intern Med 2024 May-Jun;38(3):1290-1299.
    doi: 10.1111/jvim.17047pubmed: 38497217google scholar: lookup
Subscribe to our newsletter
Join 99,824 horse owners like you who receive our email updates on horse health and nutrition.