Equine Herpesvirus-1 Outbreak During a Show-Jumping Competition: A Clinical and Epidemiological Study.
Abstract: A total of 752 horses were involved in the CES Valencia Spring Tour 2021. Due to an equine herpesvirus-1 (EHV-1) outbreak, the competition was cancelled and the site was locked down. The objective of this study was to describe epidemiological, clinical, diagnostic, and outcome data of the 160 horses remaining in Valencia. Clinical and quantitative polymerase chain reaction (qPCR) data were analysed for 60 horses in a retrospective case-control observational study. The risk of developing clinical manifestations was explored using a logistic regression approach. EHV-1 was detected by qPCR, genotyped as A2254 (ORF30) and isolated on cell culture. From the 60 horses, 50 (83.3%) showed fever, 30 horses (50%) showed no further signs and 20 (40%) showed neurological signs, with eight horses (16%) hospitalised, of which two died (3%). Stallions and geldings were six times more likely to develop EHV-1 infection compared to mares. Horses older than 9 years, or housed in the middle of the tent were more likely to develop EHV-1 myeloencephalopathy (EHM). These data show that for EHV-1 infection, the risk factor was male sex. For EHM the risk factors were age > 9-year old and location in the middle of the tent. These data highlight the crucial role of stable design, position, and ventilation in EHV-outbreaks. It also showed that PCR testing of the horses was important to manage the quarantine.
Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.
Publication Date: 2023-06-18 PubMed ID: 37339699DOI: 10.1016/j.jevs.2023.104869Google Scholar: Lookup
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- Observational Study
- Veterinary
- Journal Article
- Clinical Study
- Diagnosis
- Diagnostic Technique
- Disease Diagnosis
- Disease Etiology
- Disease Outbreaks
- Epidemiology
- Equine Health
- Equine Herpesvirus
- Horses
- Infection
- Infectious Disease
- Mares
- Observational Study
- Polymerase Chain Reaction
- Risk Factors
- Showjumping
- Stallion
- Veterinary Care
- Veterinary Medicine
- Veterinary Research
Summary
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This research explores an outbreak of equine herpesvirus-1 (EHV-1) during a horse show in Valencia in 2021. The authors discovered that certain factors, such as the sex and age of the horse as well as their location within the stables, played a significant role in the likelihood of EHV-1 infection and the development of potentially fatal complications.
Study Context and Aims
The study was carried out in the aftermath of a significant outbreak of EHV-1 at a show-jumping competition in Valencia in 2021. The goal of the research was to gather and evaluate epidemiological, clinical, diagnostic data, and the outcome of the remaining 160 horses onsite after the competition was cancelled. The study also aimed to identify risk factors associated with the manifestation of clinical symptoms of EHV-1, including the more severe condition, EHV-1 myeloencephalopathy (EHM).
- The researchers used quantitative polymerase chain reaction (qPCR) to test for EHV-1. The virus they detected was genotyped as A2254.
- The data was analysed using logistic regression, a statistical model frequently used in medical and social sciences for its capacity to predict two-way outcomes.
Key Findings
The research identified a number of directives which could influence the likelihood of a horse contracting EHV-1 and developing EHM.
- 83.3% of the 60 horses studied presented a fever, an initial sign of EHV-1 infection.
- 50% of the horses did not develop any further symptoms, while the other half displayed neurological signs. This indicated progression to EHM.
- Two of the eight hospitalised horses died, attributing to a mortality rate of 3% among affected horses.
- Male horses (stallions and geldings) were six times more likely than mares to contract EHV-1.
- Older horses (above 9 years) and horses kept in the middle of the tent were more prone to develop EHM, the severe complication of EHV-1 infection.
Implications of the Findings
The research sheds light on key risk factors that make horses more susceptible to EHV-1 infection and to progression to EHM.
- Gender and age were identified as risk factors for infection and EHM respectively. This indicates a possible need for targeted preventative measures.
- The significant risk associated with the horse’s location within the stables underscores the importance of stable design, arrangement and ventilation in managing EHV-1 outbreaks. This finding suggests that improvements in stable design could potentially reduce the risk of outbreaks.
- The successful use of PCR testing also highlighted its importance in managing quarantine protocols, aiding in early detection and helping prevent virus spread.
Overall, the study contributes towards further understanding of EHV-1 and potentially developing better prevention and management strategies in the event of an outbreak.
Cite This Article
APA
Couroucé A, Normand C, Tessier C, Pomares R, Thévenot J, Marcillaud-Pitel C, Legrand L, Pitel PH, Pronost S, Lupo C.
(2023).
Equine Herpesvirus-1 Outbreak During a Show-Jumping Competition: A Clinical and Epidemiological Study.
J Equine Vet Sci, 128, 104869.
https://doi.org/10.1016/j.jevs.2023.104869 Publication
Researcher Affiliations
- BIOTARGEN UR7450, Université de Caen Normandie, Caen, France; RESPE, 3 rue Nelson Mandela, Saint Contest, France; ONIRIS, CISCO-ONIRIS, Route de Gachet, Nantes, Cedex, France. Electronic address: anne.courouce@oniris-nantes.fr.
- BIOTARGEN UR7450, Université de Caen Normandie, Caen, France; LABÉO, 1 route de Rosel, Saint Contest, France.
- ONIRIS, CISCO-ONIRIS, Route de Gachet, Nantes, Cedex, France.
- Clinique vétérinaire, LD Le Tremoulet, Legeuvin, France.
- Clinique vétérinaire, 1600 Roqueville, Issus, France.
- RESPE, 3 rue Nelson Mandela, Saint Contest, France.
- BIOTARGEN UR7450, Université de Caen Normandie, Caen, France; LABÉO, 1 route de Rosel, Saint Contest, France.
- LABÉO, 1 route de Rosel, Saint Contest, France.
- BIOTARGEN UR7450, Université de Caen Normandie, Caen, France; LABÉO, 1 route de Rosel, Saint Contest, France.
- RESPE, 3 rue Nelson Mandela, Saint Contest, France.
MeSH Terms
- Horses
- Animals
- Male
- Female
- Herpesvirus 1, Equid / genetics
- Retrospective Studies
- Horse Diseases / epidemiology
- Case-Control Studies
- Disease Outbreaks / veterinary
- Herpesviridae Infections / epidemiology
- Herpesviridae Infections / veterinary
Conflict of Interest Statement
Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Citations
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