West Nile Virus Infiltrates the Upper 48; EEE Sprinkled Throughout

Every state in the 48 contiguous United States has now experienced a taste of West Nile virus (WNV) since it first was detected in the Western Hemisphere in 1999. Having their first encounters with West Nile virus this year were Nevada (WNV found in birds, mosquitoes, horses, and humans) and Oregon (in birds and horses).

By Aug. 26, the USDA had reported 351 equine cases in 28 states. The three states with the most equine cases were Arizona, California, and Wyoming. California’s equine cases have steadily risen--WNV was confirmed in 158 horses by Aug. 26, and 82 of those died or were euthanized. Another 51 cases were pending confirmation. Arizona had logged 67 equine cases by Aug. 30, and 27 Wyoming cases were reported.

Vets still hold that mosquito source reduction and vaccination are a horse owner's best bets for preventing WNV. There are two fully approved equine vaccines, each of which requires an initial series of vaccinations followed by boosters given periodically.

EEE Hits
By Sept. 1, mosquito season was well underway and Eastern equine encephalitis (EEE) had reared its head in several states, with cases reported in Alabama, Delaware, Florida, New Jersey, New York, Texas, and Virginia.

Last year was an epidemic year for Florida (207 cases in 50 counties), but 2004 has been an average EEE year, with 29 cases from 19 counties by Sept. 1.

Again, mosquito eradication and vaccination measures are recommended for protecting horses against this disease.

Learn more about West Nile Virus and Eastern Equine Encephalitis.

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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