Aug. 29, 2013 -- The Kentucky State Veterinarian's office noted the first confirmed case of EEE affecting a Kentucky resident horse since 2008, and only the second reported naturally infected horse in Kentucky since 1995.
Murray State University's Breathitt Veterinary Center (BVC) contacted the Kentucky State Veterinarian's Office and reported testing conducted on equine serum forwarded by the BVC to USDA's National Veterinary Services Laboratory had been reported positive for Eastern equine encephalitis virus IgM (antibody) by an ELISA assay.
Following conversation with the horse’s owner, and in consultation with the attending veterinarian, a diagnosis of Eastern equine encephalitis (EEE) having affected the horse was confirmed and the Cabinet for Health Services’ Department of Public Health was notified of this diagnosis on Friday evening.
The case is described as follows:
EEE diagnosis based on clinical presentation consistent with EEE infection and a Positive EEEv IgM by ELISA testing reported by USDA's National Veterinary Services Laboratory.
In Hart County Kentucky: a 10-year-old gelding Tennessee walking horse died. His onset of symptoms started Aug. 16, 2013, which the owner described the horse as being listless, sleepy and unwilling/unable to eat.
The horse was presented to a veterinarian on Aug. 17 showing symptoms of being lethargic, reluctant to move, head tilt, mild muscle fasciculation, febrile, unable to eat and head tilt. The patient worsened throughout the day, developed seizures, and became recumbent unable to rise. The horse expired on Aug. 18 (about 48 hours of illness duration).
West Nile testing was negative.
The horse had no history of West Nile virus or EEE vaccination within the past 36 months. The gelding was a resident of Hart County, Kentucky, with no recent travel history. Observation of 19 other horses on premises showed none with signs of illness, and all were were vaccinated Aug. 17.
Clinical signs associated with the disease commonly include high fever, depression, lack of appetite and neurologic abnormalities described as paralysis, inability or difficulty swallowing, sleepy, ataxia. The fatality rate of horses infected with EEE is reported to be as high as 75-80%, with death frequently occurring within a day or two after onset.
Strategies utilized to mitigate risk of exposure to West Nile virus can be effective in combating EEE. In addition to reducing disease transmission by minimizing mosquito habitat, effective equine vaccines for EEE and WNV are available. The Kentucky State Veterinarian's office encourages horse owners to consult their veterinarians to determine the immunity status of their animals and, if needed, to stimulate additional immunity.
Through Aug. 27, 2013, the Centers for Disease Control has reported 70 veterinary (presumably equine) and three human cases of Eastern equine encephalitis being diagnosed in the United States this calendar year. A geographic reference for these cases can be seen at http://diseasemaps.usgs.gov/eee_us_veterinary.html.
The American Association of Equine Practitioners web page includes information describing this disease and can be found at http://www.aaep.org/eee_wee.htm.
The Kentucky Department of Agriculture’s West Nile virus web page has been updated to reflect this EEE case and can be seen by following the link to www.kyagr.com/statevet/equine-infectious-diseases.html#west.