LEXINGTON, Ky. — As West Nile virus (WNV) spreads across the country in alarming numbers, Kentucky is seeing both human and equine cases. As of last week two human cases have been confirmed, and a total of seven horses have been diagnosed with the disease.

The first human case was discovered in Henry County, and the Louisville Metro Health Department reported another case in Jefferson County Aug. 24. Kentucky and neighboring Tennessee, however, have not seen the outbreaks experienced in other states such as Texas. In fact, Texas has seen half of all cases, according to the Centers for Disease Control and Prevention (CDC).

In Kentucky, no human fatalities have resulted from the disease, but of the seven horses stricken, three have been euthanized. Dr. Craig Carter, director of the University of Kentucky Veterinary Diagnostic Lab (UKVDL), said it is still the high-risk part of the season and horse owners should be looking for signs in their animals.

“As a horse owner or veterinarian, good surveillance is the key,” he said. “Watch for a horse with neurological signs. Vaccination is not perfect, but it can often prevent and/or mitigate the illness.

“The good news is there is no evidence of person-to-person or animal-to-person infection. People are infected by the bite of a mosquito. Of course, you must always keep rabies in the back of your mind when dealing with animals that present neurological signs.”

Kentucky ag officials have been encouraging horse owners to vaccinate for the disease since last March when a warmer than normal spring prompted warnings of possible increases in WNV cases. Carter said vaccination, even at this point, will help.

“We wanted to get the word out so folks could really consider the vaccine. It’s not perfect, like any vaccine but it is one the things that can help,” he said.

Kentucky State Veterinarian Dr. Robert Stout said effective vaccines are widely available to aid in the prevention of WNV infection. “I strongly advise horse owners to consult their veterinarians for implementation of a vaccination program. Virtually all cases seen in Kentucky have been in either non-vaccinated or under-vaccinated horses,” he said.

There are signs owners show be aware of, such as lack of voluntary coordination of muscle movements. Other symptoms may include blindness, loss of motion in the hind limbs, circling, falling and anorexia, according to information from UK.

WNV and was first discovered in Kentucky in 2001. The following year, 513 equine cases were reported. Since then, thanks to an aggressive campaign to inform horse owners of the need for vaccinations, only one case was reported in 2011.

Carter said since those days, it was thought herd immunity could fight the disease, but with weather conditions being just right for a WNV surge, it has become apparent large outbreaks can still occur.

“I imagine this is going to generate some other investigations on exactly, epidemiologically, how are we going to see WNV in the future,” he said. “Is this just due to unusual mosquito populations this year? All this still remains to be figured out.”

Rusty Ford, equine programs manager for the Kentucky Department of Agriculture, said anything that can be done to reduce mosquito habitats should be one of the first things horse owners try to prevent the disease. He also agreed it’s not too late to vaccinate.

“If you look historically, we will usually peak on West Nile activity about the third week of September. That’s when we’ve reached the top,” he said. “We’ll continue to see cases perhaps through October, maybe even into November, depending on the weather patterns. 

If you haven’t yet vaccinated, there still may be a benefit to consulting your veterinarian and establishing some immunity in your equine.”

In Tennessee, only one case of equine WNV has been discovered so far but six human cases have been diagnosed. State officials are informing the public to be on alert for the reemergence of viruses transmitted by mosquitoes, according to information from the Tennessee Department of Agriculture (TDA).

“The risk for West Nile virus transmission is high in Tennessee, particularly in Shelby County,” said State Medical Entomologist Abelardo Moncayo, Ph.D. “The best way to protect yourself is to prevent mosquito bites, and there are simple precautions we can all take to reduce our contact with mosquitoes and our risk of bites.”

A TDA press release noted: “Health officials identified WNV-positive pools of mosquitoes in Tennessee locations in the first week of May, much earlier than in a typical summer. Currently, in Shelby County (located in the extreme western portion of the state) in August, 60 percent of mosquito pools submitted for testing have been positive for West Nile virus.”

From an equine standpoint TDA recommends owners review their records and vaccinate their horses for the disease.

For assistance in Kentucky, horse owners can contact the UKVDL at 859-257-8283 or the Breathitt Veterinary Center in Hopkinsville at 270-886-3959. In Tennessee, contact the state veterinarian’s office and diagnostic laboratory at 615-837-5120.

More information on WNV is available on the Tennessee Department of Health website at http://health.state.tn.us/

ceds/WNV/wnvhome.asp or at www.cdc.gov/ncidod/dvbid/westnile/wnv_factsheet.htm