Horse in Missouri has confirmed case of West Nile Virus

By Steve Moyer

Nevada Daily Mail

Dr. Gayle Johnson, of the University of Missouri-Columbia, verified this year's first case of West Nile Virus in a horse. Johnson said that although the numbers of West Nile cases may decrease this summer a large number of birds, mosquitoes and other animals might still carry the virus. "We expect to see steady to declining numbers of clinical West Nile cases in domestic animals this summer," Johnson said. "Reported cases in horses have significantly decreased, although there has been one positive case in Missouri thus far in 2005."

Local veterinarian Dr. Brad Copeland said that the decline could be due to a combination of factors including the two vaccines available to horses, an increased natural immunity due to exposure to the virus and the fact that the virus could have simply run its course, but he cautioned that precautions should still be taken. "There may be less of it but it is certainly still out there and we're still susceptible to it. First I'd say cut back on mosquito habitat, clean up around the property to eliminate any standing water where mosquitoes breed. Second; wear appropriate clothing. For horses I'd still recommend an annual vaccination to protect them from the virus."

Johnson said essentially the same thing. "There are two vaccines for horses that are very effective and the population that didn't get West Nile is getting more solidly immune," she said. "There are a number of steps people can take to protect themselves and their animals, including wearing long-sleeved shirts, long pants and insect repellent when going outside at dusk or dawn. Put insect repellent on pets and horses, and try to keep them inside during peak hours of mosquito feeding. Contact a veterinarian to learn about the vaccines for horses and mosquito control for dogs."

Johnson warned that pet owners should be sure of what type of product is safe for their pet. "Products that are safe for dogs may be toxic for cats," Johnson said. "If people suspect that they or their animals have contracted the virus, they should contact a physician or veterinarian or their county health department."

The West Nile Virus was first detected in the Western Hemisphere in New York in 1999. The number of West Nile cases in Missouri peaked in 2002 with 676 reported cases in horses, 227 in birds and 168 in people. Last summer, these numbers dropped to less than 20 cases in horses, 116 in birds and 36 in people.

According to the Centers for Disease Control, four out of five people infected by West Nile will not develop any symptoms. The elderly are more likely to develop symptoms, which may include fever, headache, body aches and disorientation. People and animals that live in areas with a large mosquito population also have a higher risk of contracting the disease.

Less than 50 percent of people usually wear insect repellent, and according to the CDC, there have been more than 16,000 cases of human West Nile Virus since it was first detected in the United States.

Johnson recommends that people be alert for dead birds, especially crows and blue jays, as previous research has shown they are a good predictor for the occurrence of human cases.