The Louisiana Boll Weevil Eradication Program is doing its part to help combat the growing West Nile virus epidemic in the state, officials with the Louisiana Department of Agriculture and Forestry said.
Trucks normally used in the LDAF's boll weevil eradication efforts have been retrofitted with foggers that will spray for mosquitoes in towns and municipalities that lack mosquito abatement programs, said Bob Odom, Louisiana Commissioner of Agriculture.
“The Boll Weevil Eradication Program will continue to fully function during the mosquito spraying,” Odom said. “But because of weather conditions and prices for cotton, our acreage has been greatly reduced this year, and we can spare these trucks. Next year the story may be different if cotton acreage returns to normal.”
The department is sending out 10 trucks statewide. A team of entomologists, Mosquito Control Association members, LDAF officials and Department of Health and Hospitals officials will design a plan for spraying in critical locations.
“After receiving requests for spraying, we will strategically plan the coordination of our efforts based on scientific data for mosquitoes in those areas,” Odom said. Towns and municipalities that request spraying will have to pay for the chemical used and any overnight expenses incurred by the driver, and the department will provide the truck and driver.
So far this year, the Center for Disease Control and DHH have confirmed at least 85 cases of West Nile virus in humans in Louisiana and five deaths. LDAF has confirmed 118 cases of West Nile virus in horses and expects more confirmations later this week.
“The problem with tracking this disease in horses and humans is that many times it goes undetected. When a healthy person or animal is infected, he may never know,” Odom said. “Mild symptoms may occur and eventually go away without a veterinarian or doctor ever being called in to help. I'm not sure we'll ever find out how many people or animals actually have this virus.”
Significant outbreaks of West Nile virus in horses are occurring in the Florida parishes below the Mississippi line and in the southwest corner of the state in Cameron and Calcasieu parishes. West Nile has been confirmed in humans and birds in northeast Louisiana this summer, including Ouachita parish and four neighboring parishes where there was a severe encephalitis epidemic last year.
Odom and LDAF State Veterinarian Dr. Maxwell Lea recommend vaccinating horses for West Nile virus once every six months. The initial vaccination requires that a horse receive a first injection and then a second injection three to four weeks later. Following that round of vaccine, a booster every six months is needed, Lea said. Vaccine is available through local veterinarians.
“I also want to urge horse owners to keep up their annual vaccinations for Eastern and Western Equine encephalitis. Right now we're focusing a lot of attention on West Nile virus vaccination, but we can't forget about these other fatal diseases,” Odom said.
West Nile virus was first diagnosed in Louisiana horses last year when nine cases were confirmed in equine animals.
Symptoms of West Nile virus in horses are similar to those of Eastern Equine encephalitis and include lethargy, increase in temperature, head pressing and finally, the inability to stand or walk. Eastern Equine is another encephalitis causing virus that is spread by mosquitoes and affects horses in Louisiana.
West Nile virus is fatal in about 30 percent of the horses that contract it, whereas Eastern Equine encephalitis has a mortality rate of 90 percent. The disease causes encephalitis, or swelling of the brain, in both horses and humans, but cannot be transmitted directly from horses or humans to other horses and humans. Mosquitoes in two ways transmit the virus, either from bird to bird or from bird to mammal.