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Animals : an open access journal from MDPI2022; 13(1); doi: 10.3390/ani13010059

Equine Herpesvirus Type 1 Myeloencephalitis in the Brazilian Amazon.

Abstract: An investigative and epidemiological study was carried out for equine herpesvirus type 1 (HVE-1) in 10 outbreaks of neurological disease from different farms in the state of Pará, Brazil. 25 horses were studied: six male and 19 females, aged between one and 13 years. A necropsy of six horses was performed, and the others recovered either with or without treatment (T1-vitamin B1 + dexamentasone; T2-vitamin B1 + flunixim meglumine). Animals that received treatment recovered after eight days. The main clinical signs observed were motor incoordination, progressive paresis, thoracic and/or pelvic limbs abducted after induction of clinical examination, knuckling of the hind fetlocks, sagging and swaying of the hindquarters while standing or walking and paresis. All animals were positive: 88% (22/25) in nested PCR and 72% (18/25) in serum neutralization (including three negatives in serology). Focal brownish areas compatible with hemorrhage were found in the white and gray matter of the spinal cord of two animals. On histological analysis, there were perivasculitis and neutrophilic vasculitis in the gray matter of the spinal cord and brain. Based on the evidence, this work proves the circulation of HVE-1 in the Amazon biome, mainly in the state of Pará, Brazil.
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Publication Date: 2022-12-23 PubMed ID: 36611668PubMed Central: PMC9817990DOI: 10.3390/ani13010059Google Scholar: Lookup
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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 outbreaks of neurological disease in horses in the state of Pará, Brazil, attributing the condition to equine herpesvirus type 1 (EHV-1). Researchers found that the virus circulated mainly in this state, marking the first documented instance of this disease in the Amazon biome.

Research Methodology

  • The research was conducted using a sample of 25 horses, which included 19 females and six males, all ranging in age from one to 13 years.
  • The team investigated 10 outbreaks of a neurological condition suspected to be caused by EHV-1 in different farms across the state of Pará.
  • Six of the horses were subjected to a necropsy, while the rest were observed for their recovery, with and without treatment.
  • The treatment regime consisted of two types; T1 treatment involved vitamin B1 and dexamethasone, while T2 included vitamin B1 and flunixin meglumine. Those treated exhibited recovery after approximately eight days.

Clinical Symptoms

  • The horses displayed key clinical signs, including motor incoordination, progressive paresis, abduction of the thoracic and/or pelvic limbs, hind fetlock knuckling, and sagging and swaying of the hindquarters while standing or walking.

Findings

  • Nearly every horse in the study tested positive for EHV-1, with 88% (22 out of 25) showing positive results in a nested Polymerase Chain Reaction (PCR) test, and 72% (18 out of 25) showing positive results in a serum neutralization test.
  • Post-mortem examinations of two horses showed brownish areas in the spinal cord’s white and gray matter, indicative of hemorrhage.
  • Furthermore, histological analysis revealed cases of perivasculitis and neutrophilic vasculitis in the gray matter of the spinal cord and brain.
  • These findings confirm the presence of EHV-1 among horses in the Amazon biome, particularly within the state of Pará, Brazil, signifying an epidemiological concern for horse health in this region.

Cite This Article

APA
Barbosa JD, Lins AMC, Bomjardim HDA, Silveira NDSES, Barbosa CC, Beuttemmuller EA, Brito MF, Salvarani FM. (2022). Equine Herpesvirus Type 1 Myeloencephalitis in the Brazilian Amazon. Animals (Basel), 13(1). https://doi.org/10.3390/ani13010059

Publication

Animals : an open access journal from MDPI
ISSN: 2076-2615
NlmUniqueID: 101635614
Country: Switzerland
Language: English
Volume: 13
Issue: 1

Researcher Affiliations

Barbosa, José Diomedes
  • Instituto de Medicina Veterinária, Universidade Federal do Pará, Castanhal 68740-970, PA, Brazil.
Lins, André de Medeiros Costa
  • Instituto de Medicina Veterinária, Universidade Federal do Pará, Castanhal 68740-970, PA, Brazil.
Bomjardim, Henrique Dos Anjos
  • Instituto de Estudos do Trópico Úmido (IETU), Universidade Federal do Sul e Sudeste do Pará (Unifesspa), Xinguara 68557-335, PA, Brazil.
Silveira, Natália da Silva E Silva
  • Instituto de Medicina Veterinária, Universidade Federal do Pará, Castanhal 68740-970, PA, Brazil.
Barbosa, Camila Cordeiro
  • Instituto de Medicina Veterinária, Universidade Federal do Pará, Castanhal 68740-970, PA, Brazil.
Beuttemmuller, Edsel Alves
  • Centro de Ciências Agrárias, Universidade Estadual de Londrina (UEL), Londrina 86057-070, PR, Brazil.
Brito, Marilene Farias
  • Departamento de Epidemiologia e Saúde Pública (DESP), Instituto de Veterinária (IV), Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica 23890-000, RJ, Brazil.
Salvarani, Felipe Masiero
  • Instituto de Medicina Veterinária, Universidade Federal do Pará, Castanhal 68740-970, PA, Brazil.

Conflict of Interest Statement

The authors declare no conflict of interest.

References

This article includes 43 references
  1. Lecollinet S, Pronost S, Coulpier M, Beck C, Gonzalez G, Leblond A, Tritz P. Viral Equine Encephalitis, a Growing Threat to the Horse Population in Europe?. Viruses 2019;12:23.
    doi: 10.3390/v12010023pmc: PMC7019608pubmed: 31878129google scholar: lookup
  2. King AMQ, Adams MJ, Carstens EB, Lefkowitz EJ. Virus Taxonomy: Ninth Report of the International Committee on Taxonomy of Viruses. Elsevier; Amsterdam, The Netherlands: 2012.
  3. Allkofer A, Garvey M, Ryan E, Lyons R, Ryan M, Lukaseviciute G, Walsh C, Venner M, Cullinane A. Primary Vaccination in Foals: A Comparison of the Serological Response to Equine Influenza and Equine Herpesvirus Vaccines Administered Concurrently or 2 Weeks Apart. Arch. Virol. 2021;166:571–579.
    doi: 10.1007/s00705-020-04846-6pubmed: 33410993google scholar: lookup
  4. Galindo D, Rivera H, Ramírez M, Manchego A, Mantilla J, Valderrama W. Seroprevalencia Del Virus de La Rinoneumonitis En Caballos (Equus Caballus) Del Perú. Rev. Investig. Vet. Perú 2015;26:342.
    doi: 10.15381/rivep.v26i2.11005google scholar: lookup
  5. Da Silva AA, Cunha EMS, Lara MDCCDSH, Villalobos EMC, Nassar AFDC, Mori E, Zanuzzi CN, Galosi CM, Del Fava C. Low Occurrence of Equine Herpesvirus 1 (EHV-1) as Cause of Abortion and Perinatal Mortality in Brazil. Arq. Inst. Biol. 2018;85:1–7.
    doi: 10.1590/1808-1657000852017google scholar: lookup
  6. Costa EA, Rosa R, Oliveira TS, Assis AC, Paix�o TA, Santos RL. Molecular Characterization of Neuropathogenic Equine Herpesvirus 1 Brazilian Isolates. Arq. Bras. Med. Vet. Zootec. 2015;67:1183–1187.
    doi: 10.1590/1678-4162-7427google scholar: lookup
  7. Estima-Silva P, Riet-Correa F, Coelho ACB, Echenique JVZ, Marcolongo-Pereira C, Lima M, Diel DG, Schild AL. Identification of Equine Herpesvirus Type 1 as Cause of Abortion in Mares in Southern Brazil. Arq. Bras. Med. Vet. Zootec. 2019;71:1421–1424.
    doi: 10.1590/1678-4162-10430google scholar: lookup
  8. Pusterla N, Barnum S, Miller J, Varnell S, Dallap-Schaer B, Aceto H, Simeone A. Investigation of an EHV-1 Outbreak in the United States Caused by a New H752 Genotype. Pathogens 2021;10:747.
    doi: 10.3390/pathogens10060747pmc: PMC8231618pubmed: 34199153google scholar: lookup
  9. Cruz F, Fores P, Mughini-Gras L, Ireland J, Moreno MA, Newton JR. Seroprevalence and Factors Associated with Equine Herpesvirus Type 1 and 4 in Spanish Purebred Horses in Spain. Vet. Rec. 2016;178:398.
    doi: 10.1136/vr.103573pubmed: 26984900google scholar: lookup
  10. 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;13:1429.
    doi: 10.3390/v13081429pmc: PMC8402800pubmed: 34452295google scholar: lookup
  11. Muniz TDPTP, do Carmo Custódio De Souza Hunold Lara M, Villalobos EMC, Pinheiro JW, de Oliveira ERG, Carneiro GF. Sero-Epidemiological and Reproductive Survey for Alphaherpesvirus Infections in Horses in the State of Pernambuco, Brazil. Semin. Cienc. Agrar. 2020;41:1079–1086.
    doi: 10.5433/1679-0359.2020v41n3p1079google scholar: lookup
  12. Costa EA, Rosa R, Oliveira TS, Furtini R, Fonseca Júnior AA, Paixão TA, Santos RL. Diagnóstico Etiológico de Enfermidades Do Sistema Nervoso Central de Equinos No Estado de Minas Gerais, Brasil. Arq. Bras. Med. Vet. Zootec. 2015;67:391–399.
    doi: 10.1590/1678-6765google scholar: lookup
  13. Da Silva AA, Villalobos EMC, Cunha EMS, Lara MDCCDSH, Nassar AFDC, Piatti RM, Castro V, Pinheiro ES, De Carvalho AF, Del Fava C. Causes of Equine Abortion, Stillbirth, and Perinatal Mortality in Brazil. Arq. Inst. Biol. 2020;87:1–9.
    doi: 10.1590/1808-1657000092020google scholar: lookup
  14. Negussie H, Gizaw D, Tessema TS, Nauwynck HJ. Equine Herpesvirus-1 Myeloencephalopathy, an Emerging Threat of Working Equids in Ethiopia. Transbound. Emerg. Dis. 2017;64:389–397.
    doi: 10.1111/tbed.12377pubmed: 26010868google scholar: lookup
  15. Lunn DP, Davis-Poynter N, Flaminio MJBF, Horohov DW, Osterrieder K, Pusterla N, Townsend HGG. Equine herpesvirus-1 consensus statement. J. Vet. Intern. Med. 2009;23:450–461.
    doi: 10.1111/j.1939-1676.2009.0304.xpubmed: 19645832google scholar: lookup
  16. Barbić L, Lojkić I, Stevanović V, Bedeković T, Starešina V, Lemo N, Lojkić M, Madić J. Papers: Two Outbreaks of Neuropathogenic Equine Herpesvirus Type 1 with Breed-Dependent Clinical Signs. Vet. Rec. 2012;170:227.
    doi: 10.1136/vr.100150pubmed: 22262701google scholar: lookup
  17. Heinemann MB, Lara MCCSH. Herpesvírus Equino 1 e 4. In: Megrid J., Ribeiro M.G., Paes A.C., editors. Doenças Infecciosas em Animais de Produção e de Companhia. Roca; Rio de Janeiro, Brazil: 2016. pp. 723–729.
  18. Lara MCCSH, Cunha EMS, Villalobos EMC, Nassar AFC, Asano KM, Fernandes WR, Richtzenhain LJ, Brandão PE, Mori E. First Isolation of Equine Herpesvirus Type 1 From a Horse With Neurological Disease in Brazil. Arq. Inst. Biol. 2008;75:221–224.
    doi: 10.1590/1808-1657v75p2212008google scholar: lookup
  19. Costa EA, Lima GBL, Castro RT, Furtini R, Portilho RV, Resende M. Meningoencephalitis in a Horse Associated with Equine Herpesvirus 1. Arq. Bras. Med. Vet. Zootec. 2008;60:1580–1583.
    doi: 10.1590/S0102-09352008000600044google scholar: lookup
  20. Costa ÉA, Vasconcelos AC, Bomfim MRQ, Silva MX, Haddad JPA, Amorim HB, Lima GBL, Furtini R, Resende M. Epidemiological and Clinical Aspects of Equine Herpesvirus Encephalitis Infection in Horses That Died with Neurological Signs from Minas Gerais State, Brazil. Braz. J. Vet. Res. Anim. Sci. 2009;46:262–272.
    doi: 10.11606/issn.1678-4456.bjvras.2009.26774google scholar: lookup
  21. Mori E, Borges AS, Delfiol DJZ, Oliveira Filho JP, Gonçalves RC, Cagnini DQ, Lara MCCSH, Cunha EMS, Villalobos EMC, Nassar AFC. First Defection of the Equine Herpesvirus 1 Neuropathogenic Variant in Brazil. OIE Rev. Sci. Tech. 2011;30:949–954.
    doi: 10.20506/rst.30.3.2090pubmed: 22435205google scholar: lookup
  22. Cunha EMS, Lara MCCSH, Villalobos EMC, Nassar AFC, Del Fava C, Scannapieco EM, Cunha MS, Mori E, Gomes MN. Investigation of Neurological Diseases in Equine Tested Negative for Rabies. Rev. Educ. Contin. CRMV-SP 2011;9:43.
  23. Boom R, Sol CJA, Salimans MMM, Jansen CL, Wertheim-Van Dillen PME, van der Noordaa J. Rapid and Simple Method for Purification of Nucleic Acids. J. Clin. Microbiol. 1990;28:495–503.
    doi: 10.1128/jcm.28.3.495-503.1990pmc: PMC269651pubmed: 1691208google scholar: lookup
  24. Borchers K, Slater J. A Nested PCR for the Detection and Differentiation of EHV-1 and EHV-4. J. Virol. Methods. 1993;45:331–336.
    doi: 10.1016/0166-0934(93)90117-Apubmed: 8106604google scholar: lookup
  25. Mekonnen A, Eshetu A, Gizaw D. Equine Herpesvirus 1 and/or 4 in Working Equids: Seroprevalence and Risk Factors in North Shewa Zone, Ethiopia. Ethiop. Vet. J. 2017;21:28.
    doi: 10.4314/evj.v21i2.3google scholar: lookup
  26. 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;27:339–346.
    doi: 10.1111/jvim.12051pubmed: 23398291google scholar: lookup
  27. 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;21:157–165.
    doi: 10.1111/j.1939-1676.2007.tb02942.xpubmed: 17338164google scholar: lookup
  28. Allen GP. Risk Factors for Development of Neurologic Disease after Experimental Exposure to Equine Herpesvirus-1 in Horses. Am. J. Vet. Res. 2008;69:1595–1600.
    doi: 10.2460/ajvr.69.12.1595pubmed: 19046006google scholar: lookup
  29. Sebastiano M, Chastel O, de Thoisy B, Eens M, Costantini D. Oxidative Stress Favours Herpes Virus Infection in Vertebrates: A Meta-Analysis. Curr. Zool. 2016;62:325–332.
    doi: 10.1093/cz/zow019pmc: PMC5829443pubmed: 29491920google scholar: lookup
  30. Ata EB, Zaghawa A, Ghazy AA, Elsify A, Shaapan RM. Equine Herpes Virus Type-1 Infection: Etiology, Epidemiology, Pathogenesis, Identification and Recent Diagnosis. Asian J. Epidemiol. 2018;11:34–45.
    doi: 10.3923/aje.2018.34.45google scholar: lookup
  31. McFadden AMJ, Hanlon D, McKenzie RK, Gibson I, Bueno IM, Pulford DJ, Orr D, Dunowska M, Stanislawek WL, Spence RP. The First Reported Outbreak of Equine Herpesvirus Myeloencephalopathy in New Zealand. N. Z. Vet. J. 2016;64:125–134.
    doi: 10.1080/00480169.2015.1096853pubmed: 26414406google scholar: lookup
  32. Maxwell LK, Bentz BG, Gilliam LL, Ritchey JW, Pusterla N, Eberle R, Holbrook TC, McFarlane D, Rezabek GB, Meinkoth J. Efficacy of the Early Administration of Valacyclovir Hydrochloride for the Treatment of Neuropathogenic Equine Herpesvirus Type-I Infection in Horses. Am. J. Vet. Res. 2017;78:1126–1139.
    doi: 10.2460/ajvr.78.10.1126pmc: PMC6440545pubmed: 28945127google scholar: lookup
  33. Pusterla N, Hatch K, Crossley B, Wademan C, Barnum S, Flynn K. Equine Herpesvirus-1 Genotype Did Not Significantly Affect Clinical Signs and Disease Outcome in 65 Horses Diagnosed with Equine Herpesvirus-1 Myeloencephalopathy. Vet. J. 2020;255:105407.
    doi: 10.1016/j.tvjl.2019.105407pubmed: 31982080google scholar: lookup
  34. van Galen G, Leblond A, Tritz P, Martinelle L, Pronost S, Saegerman C. A Retrospective Study on Equine Herpesvirus Type-1 Associated Myeloencephalopathy in France (2008–2011). Vet. Microbiol. 2015;179:304–309.
    doi: 10.1016/j.vetmic.2015.07.003pubmed: 26228835google scholar: lookup
  35. Pusterla N, Mapes S, Wademan C, White A, Estell K, Swain E. Investigation of the Role of Mules as Silent Shedders of EHV-1 during an Outbreak of EHV-1 Myeloencephalopathy in California. Vet. Rec. 2012;170:465.
    doi: 10.1136/vr.100598pubmed: 22472540google scholar: lookup
  36. Bryant NA, Wilkie GS, Russell CA, Compston L, Grafham D, Clissold L, McLay K, Medcalf L, Newton R, Davison AJ. Genetic Diversity of Equine Herpesvirus 1 Isolated from Neurological, Abortigenic and Respiratory Disease Outbreaks. Transbound. Emerg. Dis. 2018;65:817–832.
    doi: 10.1111/tbed.12809pmc: PMC5947664pubmed: 29423949google scholar: lookup
  37. Hafshejani TT, Nekoei S, Vazirian B, Doosti A, Khamesipour F, Anyanwu MU. Molecular Detection of Equine Herpesvirus Types 1 and 4 Infection in Healthy Horses in Isfahan Central and Shahrekord Southwest Regions, Iran. BioMed Res. Int. 2015;2015:917854.
    doi: 10.1155/2015/917854pmc: PMC4569764pubmed: 26421307google scholar: lookup
  38. Goehring LS, Brandes K, Ashton LV, Wittenburg LA, Olea-Popelka FJ, Lunn DP, Hussey GS. Anti-Inflammatory Drugs Decrease Infection of Brain Endothelial Cells with EHV-1 in Vitro. Equine Vet. J. 2017;49:629–636.
    doi: 10.1111/evj.12656pubmed: 27864898google scholar: lookup
  39. Mesquita LP, Costa RC, Zanatto DA, Bruhn FRP, Mesquita LLR, Lara MCCSH, Villalobos EMC, Massoco CO, Mori CMC, Mori E. Equine Herpesvirus 1 Elicits a Strong Pro-Inflammatory Response in the Brain of Mice. J. Gen. Virol. 2021;102:001556.
    doi: 10.1099/jgv.0.001556pubmed: 33528354google scholar: lookup
  40. Baltrusch S. The Role of Neurotropic B Vitamins in Nerve Regeneration. BioMed Res. Int. 2021;2021:9968228.
    doi: 10.1155/2021/9968228pmc: PMC8294980pubmed: 34337067google scholar: lookup
  41. Studdert MJ, Hartley CA, Dynon K, Sandy JR, Slocombe RR, Charles JA, Milne ME, Clarke AF, El-Hage C. Outbreak of Equine Herpesvirus Type 1 Myeloencephalitis: New Insights from Virus Identification by PCR and the Application of an EHV-1 -Specific Antibody Detection ELISA. Vet. Rec. 2003;153:417–423.
    doi: 10.1136/vr.153.14.417pubmed: 14582730google scholar: lookup
  42. Hussey GS. Key Determinants in the Pathogenesis of Equine Herpesvirus 1 and 4 Infections. Vet. Pathol. 2019;56:656.
    doi: 10.1177/0300985819849498pubmed: 31394999google scholar: lookup
  43. Holz CL, Sledge DG, Kiupel M, Nelli RK, Goehring LS, Soboll Hussey G. Histopathologic Findings Following Experimental Equine Herpesvirus 1 Infection of Horses. Front. Vet. Sci. 2019;6:59.
    doi: 10.3389/fvets.2019.00059pmc: PMC6409500pubmed: 30886853google scholar: lookup

Citations

This article has been cited 2 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. Carvalho KS, de Barros CSL, Mendonça FS, Machado M, Riet-Correa F. Diseases of the nervous system of equids in Brazil: a review. J Vet Diagn Invest 2025 Sep;37(5):729-752.
    doi: 10.1177/10406387251325881pubmed: 40443203google scholar: lookup
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