Analyze Diet
Transboundary and emerging diseases2015; 64(2); 389-397; doi: 10.1111/tbed.12377

Equine Herpesvirus-1 Myeloencephalopathy, an Emerging Threat of Working Equids in Ethiopia.

Abstract: Although equine herpesvirus myeloencephalopathy (EHM) is a sporadic and relatively uncommon manifestation of equine herpesvirus-1 (EHV-1), it has the potential for causing devastating outbreaks in horses. Up till now, there were no reported EHM outbreaks in donkeys and mules. This study describes the isolation and molecular characterization of EHV-1 from clinically EHM-affected horses (n = 6), mules (n = 3) and donkeys (n = 82) in Ethiopia during outbreaks from May 2011 to December 2013. The incidence of EHM cases was higher from April to mid-June. EHM in donkeys was more severe and death without clinical signs of paralysis, and recumbency was frequently observed. The main age of affected equines ranged from 7 to 10 years (n = 51; 56.0%), and females (n = 58; 63.7%) were more affected than males. The incidence of neuropathogenic (D ) and non-neuropathogenic (N ) variants of EHV-1 from EHM-affected equines in Ethiopia was assessed by sequencing the DNA polymerase gene (ORF30) of the EHV-1 isolates. The results indicated that from the total of 91 clinically affected equines, 90 (98.9%) of them had an ORF30 D genotype. An ORF30 N variant was only found in one donkey. Analysis of ORF68 as grouping marker for geographical differences showed that the Ethiopian EHV-1 isolates belong to geographical group 4. Due to the fatal nature of EHV-1 in donkeys, it would be interesting to examine the pathogenesis of EHM in this species. At present, there is no vaccine available in Ethiopia, and therefore, outbreaks of EHV-1 should be controlled by proper management adaptations. In addition, it is important to test the efficacy of the commercial vaccines not only in horses, but also in donkeys and mules.
Publication Date: 2015-05-26 PubMed ID: 26010868DOI: 10.1111/tbed.12377Google 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.
  • Journal Article

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 study investigates a rare and potentially devastating strain of equine herpesvirus (EHV-1), known as equine herpesvirus myeloencephalopathy (EHM), in work animals like horses, mules, and donkeys in Ethiopia. It discusses the isolation and molecular characteristics of EHV-1 from animals affected by EHM during certain outbreaks, examines the incidence and severity of the disease in various animals, and identifies the types of EHV-1 variants present in these animals.

Disease Characteristics and Affected Populations

  • The study reports that although EHM is a relatively rare condition, it can cause devastating outbreaks in horse populations. This is the first time EHM outbreaks have been reported in donkeys and mules.
  • The incidence of EHM cases was found to be higher from April to mid-June. These cases tended to involve equines of ages ranging from seven to ten years old, with a higher incidence in female than male animals.
  • EHM was found to be more severe in donkeys, often leading to death without obvious clinical signs of paralysis and recumbency.

Molecular Characterization

  • Researchers attempted to isolate and characterize EHV-1 from clinically EHM-affected equines. Their aim was to determine the variants of EHV-1 present in these animals.
  • The DNA polymerase gene (ORF30) of the EHV-1 isolates was sequenced. It was found that nearly all clinically affected equines (90 of 91, or 98.9%) had an ORF30 D genotype, representing a neuropathogenic (affecting the nervous system) variant of the virus.
  • Only one donkey was found to carry the ORF30 N variant, representing a non-neuropathogenic variant.

Geographical Analysis

  • Another aim of the study was to understand the geographical distribution of the EHV-1 strains. The ORF68 gene was analyzed as a marker for geographical differences.
  • The analysis revealed that Ethiopian EHV-1 isolates belong to geographical group 4.

Management and Control

  • The fatal nature of EHV-1 in donkeys underscores the need to understand the pathogenesis of EHM in this species.
  • Currently, there is no vaccine available in Ethiopia, meaning outbreaks of EHV-1 must be controlled by appropriate management adaptations.
  • The researchers also emphasize the importance of evaluating the effectiveness of commercial vaccines not only in horses, but in donkeys and mules as well.

Cite This Article

APA
Negussie H, Gizaw D, Tessema TS, Nauwynck HJ. (2015). Equine Herpesvirus-1 Myeloencephalopathy, an Emerging Threat of Working Equids in Ethiopia. Transbound Emerg Dis, 64(2), 389-397. https://doi.org/10.1111/tbed.12377

Publication

ISSN: 1865-1682
NlmUniqueID: 101319538
Country: Germany
Language: English
Volume: 64
Issue: 2
Pages: 389-397

Researcher Affiliations

Negussie, H
  • Laboratory of Virology, Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
  • College of Veterinary Medicine and Agriculture, Addis Ababa University, Debre Ziet, Ethiopia.
Gizaw, D
  • National Animal Health Diagnostic and Investigation Center, Sebeta, Ethiopia.
Tessema, T S
  • Institute of Biotechnology, College of Natural and Computational Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
Nauwynck, H J
  • Laboratory of Virology, Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.

MeSH Terms

  • Animals
  • DNA-Directed DNA Polymerase / genetics
  • Disease Outbreaks / veterinary
  • Equidae / virology
  • Ethiopia / epidemiology
  • Female
  • Genes, Viral / genetics
  • Genotype
  • Herpesviridae Infections / epidemiology
  • Herpesvirus 1, Equid / genetics
  • Herpesvirus 1, Equid / isolation & purification
  • Horse Diseases / epidemiology
  • Horse Diseases / virology
  • Horses
  • Incidence
  • Male

Citations

This article has been cited 21 times.
  1. Barbosa JD, Lins AMC, Bomjardim HDA, Silveira NDSES, Barbosa CC, Beuttemmuller EA, Brito MF, Salvarani FM. Equine Herpesvirus Type 1 Myeloencephalitis in the Brazilian Amazon. Animals (Basel) 2022 Dec 23;13(1).
    doi: 10.3390/ani13010059pubmed: 36611668google scholar: lookup
  2. Wondimagegnehu K, Leta S, Amenu K, Negussie H. Molecular detection and assessment of the epidemiological risk factors associated with equine herpesvirus 2 and 5 in working equids in central Ethiopia. Vet Med Sci 2022 Nov;8(6):2396-2403.
    doi: 10.1002/vms3.925pubmed: 36063540google scholar: lookup
  3. Carvelli A, Nielsen SS, Paillot R, Broglia A, Kohnle L. Clinical impact, diagnosis and control of Equine Herpesvirus-1 infection in Europe. EFSA J 2022 Apr;20(4):e07230.
    doi: 10.2903/j.efsa.2022.7230pubmed: 35414834google scholar: lookup
  4. Mureşan A, Mureşan C, Siteavu M, Avram E, Bochynska D, Taulescu M. An Outbreak of Equine Herpesvirus-4 in an Ecological Donkey Milk Farm in Romania. Vaccines (Basel) 2022 Mar 18;10(3).
    doi: 10.3390/vaccines10030468pubmed: 35335100google scholar: lookup
  5. Tong P, Duan R, Palidan N, Deng H, Duan L, Ren M, Song X, Jia C, Tian S, Yang E, Kuang L, Xie J. Outbreak of neuropathogenic equid herpesvirus 1 causing abortions in Yili horses of Zhaosu, North Xinjiang, China. BMC Vet Res 2022 Mar 1;18(1):83.
    doi: 10.1186/s12917-022-03171-1pubmed: 35232435google scholar: lookup
  6. Nielsen SS, Alvarez J, Bicout DJ, Calistri P, Canali E, Drewe JA, Garin-Bastuji B, Gonzales Rojas JL, Gortázar C, Herskin M, Michel V, Miranda Chueca MÁ, Roberts HC, Padalino B, Pasquali P, Spoolder H, Ståhl K, Calvo AV, Viltrop A, Winckler C, Carvelli A, Paillot R, Broglia A, Kohnle L, Baldinelli F, Van der Stede Y. Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): infection with Equine Herpesvirus-1. EFSA J 2022 Jan;20(1):e07036.
    doi: 10.2903/j.efsa.2022.7036pubmed: 35035581google scholar: lookup
  7. Temesgen T, Getachew Y, Negussie H. Molecular Identification of Equine Herpesvirus 1, 2, and 5 in Equids with Signs of Respiratory Disease in Central Ethiopia. Vet Med (Auckl) 2021;12:337-345.
    doi: 10.2147/VMRR.S339042pubmed: 34956854google scholar: lookup
  8. Scheurer L, Bachofen C, Hardmeier I, Lechmann J, Schoster A. Prevalence of Nasal Shedding of Equid Gammaherpesviruses in Healthy Swiss Horses. Viruses 2021 Aug 25;13(9).
    doi: 10.3390/v13091686pubmed: 34578268google scholar: lookup
  9. Câmara RJF, Bueno BL, Resende CF, Balasuriya UBR, Sakamoto SM, Reis JKPD. Viral Diseases that Affect Donkeys and Mules. Animals (Basel) 2020 Nov 25;10(12).
    doi: 10.3390/ani10122203pubmed: 33255568google scholar: lookup
  10. Goodrich EL, McLean A, Guarino C. A Pilot Serosurvey for Selected Pathogens in Feral Donkeys (Equus asinus). Animals (Basel) 2020 Oct 2;10(10).
    doi: 10.3390/ani10101796pubmed: 33023217google scholar: lookup
  11. Oladunni FS, Horohov DW, Chambers TM. EHV-1: A Constant Threat to the Horse Industry. Front Microbiol 2019;10:2668.
    doi: 10.3389/fmicb.2019.02668pubmed: 31849857google scholar: lookup
  12. Preziuso S, Sgorbini M, Marmorini P, Cuteri V. Equid alphaherpesvirus 1 from Italian Horses: Evaluation of the Variability of the ORF30, ORF33, ORF34 and ORF68 Genes. Viruses 2019 Sep 13;11(9).
    doi: 10.3390/v11090851pubmed: 31540321google scholar: lookup
  13. Garvey M, Lyons R, Hector RD, Walsh C, Arkins S, Cullinane A. Molecular Characterisation of Equine Herpesvirus 1 Isolates from Cases of Abortion, Respiratory and Neurological Disease in Ireland between 1990 and 2017. Pathogens 2019 Jan 15;8(1).
    doi: 10.3390/pathogens8010007pubmed: 30650561google scholar: lookup
  14. Matczuk AK, Skarbek M, Jackulak NA, Bażanów BA. Molecular characterisation of equid alphaherpesvirus 1 strains isolated from aborted fetuses in Poland. Virol J 2018 Dec 3;15(1):186.
    doi: 10.1186/s12985-018-1093-5pubmed: 30509297google scholar: lookup
  15. Bryant NA, Wilkie GS, Russell CA, Compston L, Grafham D, Clissold L, McLay K, Medcalf L, Newton R, Davison AJ, Elton DM. Genetic diversity of equine herpesvirus 1 isolated from neurological, abortigenic and respiratory disease outbreaks. Transbound Emerg Dis 2018 Jun;65(3):817-832.
    doi: 10.1111/tbed.12809pubmed: 29423949google scholar: lookup
  16. Stasiak K, Dunowska M, Hills SF, Rola J. Genetic characterization of equid herpesvirus type 1 from cases of abortion in Poland. Arch Virol 2017 Aug;162(8):2329-2335.
    doi: 10.1007/s00705-017-3376-3pubmed: 28451902google scholar: lookup
  17. Tallmadge RL, Laverack M, Lejeune M, Crossley B, Diel DG. A multiplex real-time PCR assay for detection of equid herpesvirus 1 and 4. Sci Rep 2025 Oct 31;15(1):38201.
    doi: 10.1038/s41598-025-22043-wpubmed: 41173927google scholar: lookup
  18. Mohamed E, Zarak I, Vereecke N, Theuns S, Laval K, Nauwynck H. Genomic analysis and replication kinetics of the closely related EHV-1 neuropathogenic 21P40 and abortigenic 97P70 strains. Vet Res 2025 Jan 13;56(1):12.
    doi: 10.1186/s13567-024-01434-3pubmed: 39806433google scholar: lookup
  19. Worku A, Molla W, Kenubih A, Negussie H, Admassu B, Ejo M, Dagnaw GG, Bitew AB, Fentahun T, Getnet K, Dejene H, Berrie K, Ibrahim SM, Gessese AT, Dessalegn B, Birhan M, Fenta MD, Kinde MZ. Molecular Detection of Equine Herpesviruses from Field Outbreaks in Donkeys in Northwest Amhara Region, Ethiopia. Vet Med Int 2024;2024:9928835.
    doi: 10.1155/2024/9928835pubmed: 39380749google scholar: lookup
  20. Tong P, Pan J, Dang Y, Yang E, Jia C, Duan R, Tian S, Palidan N, Kuang L, Wang C, Lu G, Xie J. First identification and isolation of equine herpesvirus type 1 in aborted fetal lung tissues of donkeys. Virol J 2024 May 27;21(1):117.
    doi: 10.1186/s12985-024-02390-2pubmed: 38802935google scholar: lookup
  21. Emelogu U, Lewin AC, Balasuriya UBR, Liu CC, Wilkes RP, Zhang J, Mills EP, Carter RT. Phylogenomic assessment of 23 equid alphaherpesvirus 1 isolates obtained from USA-based equids. Virol J 2023 Nov 29;20(1):278.
    doi: 10.1186/s12985-023-02248-zpubmed: 38031153google scholar: lookup