Summary & Status Of EHV-1 Incident
Equine Herpes Virus (EHV-1) infection in horses can cause respiratory disease, abortion in mares, neonatal foal death, and/or neurologic disease. The neurologic form of EHV-1 is called Equine Herpes Virus Myeloencephalopathy (EHM).
While EHV-1 and EHM are only officially listed as reportable diseases in some states, private veterinary practitioners are encouraged to notify their state animal health officials of any suspected or confirmed cases, regardless of current official state reporting requirements.
Background
Cases of EHV-1 and EHM were identified in horses that attended a National Cutting Horse Association (NCHA) event in Ogden, Utah held from April 29 to May 8, 2011. Immediately following confirmation of the EHV-1 neurological disease, the NCHA notified federal and state animal health officials that horses from their states had entered the event and may have been exposed to the virus.
The AHC and AAEP contacted USDA and requested federal coordination for data collection, dissemination, and communication efforts among state and federal veterinarians in order to mitigate the health and economic implications of further EHV-1 transmission.
In response, USDA immediately initiated an Incident Response Team comprised of state and federal animal health officials to conduct an epidemiological investigation and incident response effort on the EHV-1 disease incident and to develop a coordinated response among state, federal, and industry partners.
Status
USDA released the initial Situation Report on May 19 which reported a total of 33 confirmed EHV-1 or EHM cases in 8 states (CA, CO, ID, NM, OR, TX, UT, WA). USDA has released three subsequent Situation Reports all in one week intervals with the last report (June 8) recording a total of 88 confirmed EHV-1 or EHM cases in 10 states (AZ, CA, CO, ID, NM, NV, OK, OR, UT, WA).
Standardized recommendations were developed by state and federal officials to isolate exposed horses, monitor them for clinical signs of EHV-1, and work with private veterinary practitioners to test and treat horses affected with the disease. Biosecurity procedures have been recommended for premises with suspect and confirmed cases to mitigate further disease spread.
USDA stated the critical factor the Incident Response Team will be evaluating is the number of new exposed premises with suspect or confirmed EHV/EHM cases. The May 26th EHV-1 Situation Report recorded fifteen new premises, while the June 8th EHV-1 Situation Report recorded zero newly identified premises with suspect or confirmed cases.
After Action Review
USDA ordered an After Action Review (AAR) of the EHV-1 outbreak and invited the AHC, AAEP, NCHA and several state veterinarians to participate and provide informal verbal comments during a conference call in September 2011.
The AHC provided verbal and written comments to USDA outlining: what prompted the request for USDA assistance, what went well from USDA’s involvement, what went well from industry’s involvement, and what could have gone better.
While the health and economic impact of this most recent outbreak has yet to be fully quantified, it is certain the fallout from this incident would have been considerably worse, if not still on-going, without USDA’s efforts and partnership with state animal health officials and industry stakeholders.
AHC Position
The AHC appreciates USDA’s efforts in initiating an immediate Incident Response Team to gather, verify, and disseminate accurate information on the scope of the current incident. The AHC is also extremely grateful for the efforts and energy the EHV-1 Response Team invested to ensure state officials and stakeholders were provided with timely and accurate information on a weekly basis.
The AHC encourages individual horse owners and organizations to practice responsible biosecurity and management practices at all times to mitigate the health and economic implications of future outbreaks from all equine infectious diseases.