Prevalence of latent, neuropathogenic equine herpesvirus-1 in the Thoroughbred broodmare population of central Kentucky.
Abstract: An emerging problem of equine herpesvirus-1 (EHV-1) infection in horses in the USA is a high-mortality myeloencephalopathy that commonly occurs where large numbers of horses are stabled. EHV-1 isolates recovered from recent neurological outbreaks represent a mutant virus strain that possesses enhanced neuropathogenicity. A central question of EHV-1 myeloencephalopathy is the latency carriage rate for these mutants of EHV-1 in USA horse populations. Objective: To estimate the prevalence of neuropathogenic strains of EHV-1 as latent infections in the Thoroughbred broodmare population of central Kentucky. Methods: Submandibular lymph nodes (SMLN) were collected during post mortem examination of 132 Thoroughbred broodmares. Total DNA purified from SMLN tissue was tested for the presence of latent EHV-1 DNA by an ultrasensitive magnetic bead-based, sequence-capture, nested PCR method. Differentiation of active from latent infections by EHV-1 was achieved by detection of transcripts of EHV-1 glycoprotein B by reverse transcription PCR. Results: Latent EHV-1 DNA was detected in the SMLN tissues of 71 (54%) of the 132 mares submitted for necropsy. Thirteen (18%) of the 71 latently infected horses harboured the neuropathogenic biovar of EHV-1. Of the 13 horses latently infected with an ORF30 mutant strain of EHV-1, 11 also carried a latent, wild-type strain of the virus in their SMLN tissues. Conclusions: Neuropathogenic strains of EHV-1 have established a significant presence in the Thoroughbred broodmare population of central Kentucky as latently infected carrier horses. The data also indicate that a highly sensitive DNA detection method is required to identify many instances of EHV-1 latency. Conclusions: The presence of a relatively large biological reservoir of latent, neuropathogenic EHV-1 has the potential for posing emerging equine health and economic threats to the future prosperity of the USA horse industry.
Publication Date: 2007-12-20 PubMed ID: 18089469DOI: 10.2746/042516408X253127Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research examines the prevalence of a neuropathogenic strain of equine herpesvirus-1 (EHV-1) in the Thoroughbred broodmare population in central Kentucky. The results discovered a significant number of the tested horses were carriers of this latent virus, highlighting a potential health risk for the equine industry in the USA.
Objective and Methods of the Research
- The study was carried out with the aim of estimating the prevalence of neuropathogenic strains of EHV-1 as latent infections in the Thoroughbred broodmare population of central Kentucky.
- The research method involved collecting Submandibular lymph nodes (SMLN) from 132 Thoroughbred broodmares during post mortem examinations.
- The total DNA from these SMLN tissues was then tested for the presence of latent EHV-1 DNA. This was done using an ultrasensitive magnetic bead-based, sequence-capture, nested PCR method.
- To differentiate between active and latent EHV-1 infections, the researchers detected the transcripts of EHV-1 glycoprotein B by reverse transcription PCR.
Results of the Research
- The results showed the presence of latent EHV-1 DNA in the SMLN tissues of 54% of the horses.
- Of these latently infected horses, 18% harboured the neuropathogenic variant of EHV-1.
- Also, among the horses infected with the ORF30 mutant strain of EHV-1, the majority carried a latent, wild-type strain of the virus in their SMLN tissues.
Conclusion
- The research concluded that neuropathogenic strains of EHV-1 have established a significant presence in the Thoroughbred broodmare population of Kentucky as latently infected carrier horses.
- It also found that a highly sensitive DNA detection method was required to identify many instances of EHV-1 latency.
- The study highlights a potential biological and economic threat posed by the latent, neuropathogenic EHV-1 to the future of the USA horse industry due to the relatively large biological reservoir that has been found.
Cite This Article
APA
Allen GP, Bolin DC, Bryant U, Carter CN, Giles RC, Harrison LR, Hong CB, Jackson CB, Poonacha K, Wharton R, Williams NM.
(2007).
Prevalence of latent, neuropathogenic equine herpesvirus-1 in the Thoroughbred broodmare population of central Kentucky.
Equine Vet J, 40(2), 105-110.
https://doi.org/10.2746/042516408X253127 Publication
Researcher Affiliations
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, Kentucky 40546-0099, USA.
MeSH Terms
- Animals
- DNA, Viral / chemistry
- DNA, Viral / genetics
- Disease Outbreaks / veterinary
- Disease Reservoirs / veterinary
- Disease Reservoirs / virology
- Female
- Herpesviridae Infections / epidemiology
- Herpesviridae Infections / veterinary
- Herpesviridae Infections / virology
- Herpesvirus 1, Equid / genetics
- Herpesvirus 1, Equid / isolation & purification
- Herpesvirus 1, Equid / pathogenicity
- Herpesvirus 1, Equid / physiology
- Horse Diseases / epidemiology
- Horse Diseases / virology
- Horses
- Kentucky / epidemiology
- Lymph Nodes / virology
- Mutation
- Prevalence
- RNA, Viral / chemistry
- RNA, Viral / genetics
- Virus Latency
Citations
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