Second Confirmed Case

August 13, 2002

REYNOLDSBURG - Lab test results have confirmed the second case of West Nile virus infection in an Ohio horse, the Ohio Department of Agriculture said today. Like the first case reported last week, this horse was stabled in Holmes County but did not have the same owner, according to state Agriculture Director Fred L. Dailey.

The horse, which had not been vaccinated, was showing symptoms of infection, including tremors and rear leg weakness, when a local veterinarian collected blood samples on July 30. The samples were submitted to the Ohio Department of Agriculture?s Animal Disease Diagnostic Laboratory, which forwarded them to the National Veterinary Services Laboratory in Ames, Iowa, for testing. The horse was euthanized on Aug. 2 after its condition worsened and its veterinarian, Eric M. Shaver, D.V.M., of Berlin, sent a spinal cord sample to the state?s animal disease lab for testing. The state lab?s tests were indicative of West Nile virus, Dailey said.

Like last week?s case, this was a clinical case in which the owner observed sickness in the animal, prompting a diagnostic blood test. 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. Last July, 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. Owners should 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 Ohio Department of Agriculture for use in Ohio.

To protect people against the disease, public health authorities are continuing disease and vector surveillance activities and urging the public to adopt effective safeguards against the virus, including eliminating conditions in which mosquitoes can breed.

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 and to remove standing water from their property. "Because WNV is entrenched in Ohio, we all need to follow some simple steps to help protect ourselves from mosquito bites," Baird said. "By following this advice, we can minimize West Nile?s impact on Ohio?s health."

The state operates two toll-free telephone information lines to handle questions from the public about West Nile virus. The Ohio Department of Agriculture has a toll-free line for animal health questions, 800-300-9755, staffed 8 a.m. to 5 p.m. weekdays by the department?s Division of Animal Industry staff. Questions regarding human health should be directed to your local health department or the Ohio Department of Health?s toll-free line, 866-634-2968, staffed 8 a.m. to 4:30 p.m. weekdays by state health department personnel. Dead birds should be reported to your local health department.

The Ohio Department of Agriculture and Ohio Department of Health are members of the Ohio West Nile Virus Workgroup. Other members are the Ohio Department of Natural Resources, The Ohio State University, the Ohio Environmental Protection Agency, Association of Ohio Health Commissioners, Ohio Mosquito Control Association, Ohio Environmental Health Association, and the U.S. Department of Agriculture.