Case of West Nile virus found in McLennan County

By MINDY POEHL | Central Texas Edition

Kansas State University's Veterinary Medical Teaching Hospital was pressed into action in 2003 when West Nile put more than 50 horses in the hospital. Here, Texan, Frank Purling of Hereford, steadies his horse Mariah while student Solene Moreton administers a West Nile virus vaccination. -- Photo courtesy of Kansas State University

July 28, 2005 - The West Nile virus was detected in McLennan County on July 11. The virus was discovered in a dead blue jay found in West Waco, close to the Woodway area, said David Litke, health services supervisor with the Waco-McLennan County Public Health District.

"We rely on the public to contact us if they find freshly dead birds," Litke explained. "We (the McLennan County Public Health District) have test kits and part of the monitoring process is to test crows, blue jays and cardinals."

Blue jays and crows are in the same family and are the birds that are most susceptible to the West Nile virus. Cardinals are becoming more susceptible, too, said Litke.

"The virus is transferred by infected mosquitoes and is primarily a bird disease," said Litke. "It can be transmitted to humans and horses."

The West Nile virus is a neuro invasive disease that affects the nervous system. The virus is spread by only two of the 26 species of mosquitoes in McLennan County. Many people who are infected show no symptoms at all. "Some people will feel like they have the flu. It can progress to where people need to see a doctor. In a few cases it results in meningitis and encephalitis. If it progresses to that point, they'll receive treatment for the virus," Litke said.

"The virus is real critical for horses. They have a high death rate if they are not treated. However, there is a vaccine for horses. They are the lucky ones."

Jim Sprague, Area 2 director with the Texas Animal Health Commission, said, "Only 1 percent of horses bitten have become symptomatic," but the disease does affect the brain.

"It can make animals and people lose their coordination and cause weakness," Sprague said. "Having a vaccination is the primary thing to do and be diligent about trying to keep mosquitoes away. Put horses up in a barn at night and pour out old water. The sooner you can help an infected animal, the more expectations you can have from them. Animals are often treated with I.V. fluids or anti-inflammatories and they can get back to a normal mental state."

Litke said there are four main steps to help protect against mosquitoes. 1). Use insect repellent. DEET is one effective ingredient. 2). Remember that mosquitoes are most active in the early morning and at dusk. So, try to avoid spending time outdoors during dawn and dusk. 3). Dress appropriately. Try wearing long sleeves and pants. 4). Always be on the lookout where breeding occurs. Mosquitoes only breed in standing water that has been there a minimum of seven days.

West Nile virus was first spotted in the U.S. on the East Coast in 1999, and it resulted in one death in McLennan County in 2002. In 2004, the Health District saw no cases of the virus because of the heavy rains.

"We haven't seen as many cases as we had in 2002. Harris County was inundated with people, horses and birds who had the virus. It was a pretty major deal back then," said Sprague. "This year we've seen neurological diseases in Jefferson County. The specifics haven't changed much. The incubation period is still three to 14 days."

Sprague said the main way to verify if someone or something has West Nile is to draw a blood sample.

"It's differential - basically the virus affects the immune system," explained Sprague. "Preventative medicine is the best medicine out there, and you'll be a lot more satisfied if you know you are protected because West Nile will be with us for a while."

Litke agreed.

"The main thing is to remember that it's out there. The virus is always out there. The importance of this virus is that it is here to stay," Litke said. "Protect yourself by avoiding being bitten by mosquitoes."