Equine viral arteritis,
United Kingdom
Information received on 01/08/2019 from Dr Christine Middlemiss, Chief Veterinary Officer, DEFRA, Department for Environment,Food and Rural Affairs , London, United Kingdom
Report type Immediate notification
Date of start of the event 20/07/2019
Date of confirmation of the event 31/07/2019
Report date 31/07/2019
Date submitted to OIE 01/08/2019
Date event resolved 23/09/2019
Reason for notification Recurrence of a listed disease
Date of previous occurrence 2019
Manifestation of disease Sub-clinical infection
Causal agent Equine arteritis virus
Nature of diagnosis Laboratory (basic), Laboratory (advanced)
This event pertains to a defined zone within the country
Related reports Immediate notification (31/07/2019)
Follow-up report No. 1 (14/01/2020)
New outbreaks (1)
Outbreak 1 Shropshire, England
Date of start of the outbreak 20/07/2019
Outbreak status Resolved (23/09/2019)
Epidemiological unit Farm
Affected animals
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Equidae 5 1 0 0 0
Affected population Following a non negative test, EVA infection was confirmed by two PCR tests and gene sequencing for a semen sample taken from a stallion located in Shropshire, North England. This is the only stallion located at the premises.
Summary of outbreaks Total outbreaks: 1
Total animals affected
Species Susceptible Cases Deaths Killed and disposed of Slaughtered
Equidae 5 1 0 0 0
Outbreak statistics
Species Apparent morbidity rate Apparent mortality rate Apparent case fatality rate Proportion susceptible animals lost*
Equidae 20.00% 0.00% 0.00% 0.00%
*Removed from the susceptible population through death, destruction and/or slaughter
Source of the outbreak(s) or origin of infection
  • Unknown or inconclusive
Epidemiological comments Following non-negative results for serology and semen testing, the only stallion at the premises tested positive on two PCR tests and gene sequencing. The stallion was last bred in March 2018 to mare on same premises; normal foal produced. The stallion has not been used for semen collection for AI or covered any mare since March 2018. The stallionís owner has confirmed intention to castrate. This mitigates the risk of onward spread through breeding. Gene sequencing confirmed this case is not related to the previous EVA positives in Dorset and Devon reported in April and May respectively. Disease restrictions are to be maintained until investigations are complete.
Control measures
Measures applied
  • Movement control inside the country
  • Screening
  • Vaccination permitted (if a vaccine exists)
  • No treatment of affected animals
Measures to be applied
  • Process to inactivate the pathogenic agent in products or by-products
Diagnostic test results
Laboratory name and type Species Test Test date Result
Animal and Plant Health Agency, Weybridge (National laboratory) Equidae polymerase chain reaction (PCR) 31/07/2019 Positive
Future Reporting
The event is continuing. Weekly follow-up reports will be submitted.
Map of outbreak locations