Nine More Ohio Horses Confirmed with West Nile Virus
August 27, 2002
REYNOLDSBURG - State and federal lab test results have confirmed nine additional cases of West Nile virus infection in Ohio horses in Wayne, Gallia, Franklin, Mercer, Holmes, Tuscarawas, and Preble counties, bringing the total to 11 in the state, Fred L. Dailey, director of the Ohio Department of Agriculture, said today. The first two confirmed equine cases in Ohio were in horses stabled in Holmes County, announced by the department on Aug. 8 and 13.
Blood samples from the horses were submitted by local veterinarians to the state agriculture department?s Animal Disease Diagnostic Laboratory for testing. To confirm the results, the state lab also forwarded samples to the National Veterinary Services Laboratory in Ames, Iowa, whose findings have agreed with the state?s in every case. (NOTE TO EDITORS: See accompanying fact sheet, ?West Nile Virus Detected in Ohio Horses,? for more details on where the disease has hit the state?s equine population.)
All 11 were clinical cases in which the owner observed signs of illness in the animal, prompting a diagnostic blood test. None of the horses had been effectively vaccinated against the disease -- although one was given only the first of two required initial doses, the rest received no vaccine at all. All but two of the horses have been euthanized or have died from their illness. Routinely, the state agriculture department assists in the testing of horses and birds as part of the state?s efforts to monitor and prevent the spread of West Nile virus. In July 2001, a blue jay was the first positive indicator that West Nile virus had officially arrived in Ohio.
Horses are "sentinels" of the mosquito-borne disease rather than carriers; that is, humans can?t contract West Nile virus from an infected horse and mosquitoes don't pick up the virus from biting an infected horse. Horse owners should watch for signs of infection in their animals and should consult a veterinarian if those signs are present. Symptoms of West Nile virus in an infected horse include loss of appetite, fever, muscle tremors, weakness, paralysis of hind limbs, impaired vision, loss of coordination, aimless wandering, convulsions, inability to swallow, circling, hyper-excitability, or coma. The disease can be fatal in horses.
Dailey advised owners to consult with their veterinarians to consider vaccinating horses against the virus. The vaccine, developed by Fort Dodge Laboratories, Inc., of Fort Dodge, Iowa, was approved last year by the state agriculture department for use in Ohio.
The Ohio Department of Health is also still encouraging people to check their property for dead blue jays and crows and report them to their local health departments as part of the state?s efforts to track areas already penetrated by the disease. Although not all birds will be tested, the reporting of dead birds to local health departments is an important part of the continued surveillance effort.
Primarily a wild-bird disease, the mosquito-borne West Nile virus generally causes mild symptoms that mimic the flu in humans. In rare instances, however, WNV can cause encephalitis (inflammation of the brain) or meningitis (inflammation of the lining of the brain and spinal cord) in humans. This happens in less than 1 percent of people bitten by an infected mosquito. Those over age 50 and those with compromised immune systems are most susceptible to the serious complications related to the virus.
Ohio Department of Health Director J. Nick Baird, M.D., is urging all Ohioans to protect themselves and their loved ones from mosquito bites, remove standing water from their property, and take other preventive measures.