Venezuela: First Outbreak of VEE In Three Years

An Oct. 12 ProMED-mail posting reported that Venezuelan equine encephalitis (VEE) has re-emerged in Venezuela after being controlled by health authorities for more than three years. This virus hasn’t been reported in the United States for more than 30 years.

The ProMED posting said that representatives of the National Breeders' Federation reported that the disease has affected animals on two ranches in the state of Barinas (municipality of Arismendi). The sanitary authorities had confirmed that information.

The ProMed moderator wrote, "Venezuelan equine encephalitis virus was first isolated from a horse in Venezuela in 1938. It is closely related to Eastern equine encephalitis virus (EEE), and Western equine encephalitis virus (WEE), all three being classified as distinct species in the genus Alphavirus of the family Togaviridae. These viruses produce encephalitis in equines and humans, and differ in geographical distribution, as their names suggest."

An archived article from the University of Kentucky’s Equine Disease Quarterly (funded by underwriters at Lloyd’s of London, Brokers, and their Kentucky agents) explained that VEE occurs sporadically in Central and South America, although a major outbreak in 1969-1972 crossed the border from Mexico into Texas. Another outbreak began in May of 1995 in Venezuela and spread westward to the northernmost state of La Guajira, Colombia, in September of 1995. About 500 horses died in that outbreak, according to the Equine Disease Quarterly.

"In horses VEE causes neurologic signs of depression, incoordination, circling, blindness, and sudden death. The disease is clinically indistinguishable from Western and Eastern equine encephalitis. Diagnosis is confirmed by virus isolation and serum neutralization tests," said the Equine Disease Quarterly article.

An effective live virus vaccine is available for containment of animal disease.


About the Author

Stephanie L. Church, Editor-in-Chief

Stephanie L. Church, Editor-in-Chief, received a B.A. in Journalism and Equestrian Studies from Averett College in Danville, Virginia. A Pony Club and 4-H graduate, her background is in eventing, and she is schooling her recently retired Thoroughbred racehorse, Happy, toward a career in that discipline. She also enjoys traveling, photography, cycling, and cooking in her free time.

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