EAST TEXAS — Mosquitoes, as standard operating procedure, can make life miserable for humans, poultry, horses and livestock. This summer, there’s a chance — albeit a small one — that in East Texas a common garden variety mosquito bite can lead to death.
Texas Department of Health officials have reported occurrences of eastern equine encephalitis in East Texas. Eastern equine encephalitis (EEE) is a disease that can be fatal to both horses and humans. In Louisiana, the disease has been cycling for more than two months, killing 40 horses and an uncounted number of emus. Most recently, two humans in Louisiana have been infected, with one man still in a coma, according to Dr. Jimmy Olson, professor with Texas A&M University’s Department of entomology.
“It’s something to be concerned about. The eastern variety doesn’t just kill those with weakened immune systems like the other varieties do. It can strike down a man in the prime of life,” Olson said.
Recently, the disease has spilled over to the East Texas counties of Jasper, Harrison, Cherokee and Hardin. Though no East Texans have yet to become infected, 30 to 40 emus have died of the disease in Jasper County, while in Harrison, Cherokee and Hardin counties there are reports of horses either killed or diagnosed with the disease.
Entomologists don’t know which mosquito species transmits the disease, but they do know that Western Louisiana and East Texas are home to the same species. This week, Olson and members of his staff will be in East Texas trapping mosquitoes in hopes of determining exactly which species of mosquito is the vector.
“Until then, it would be wise to consider any mosquito suspect,” he said.
Once infected, horses begin to show clinical signs of EEE in about five days while symptoms in humans take seven to 10 days to appear. The mortality rate in horses infected with EEE is from 50 to 90 percent. The fatality rate in humans is 65 to 80 percent, according to a Texas Department of Health release.
There is an EEE vaccine for horses but not for humans. Most veterinarians should have the vaccine in stock.
Dr. James Robinson, entomologist with the Texas Agricultural Extension Service, says people can lower their risk of mosquito bites by wearing long-sleeved shirts and pants and using a mosquito repellant. The most effective products will contain Deet®, but the strength of the active ingredient will vary. Look for “Deet” or “N,N-diethyl-m-toluamide” on the list of ingredients and chose the product with the highest concentration.
Most local county Extension offices will have a publication authored by Robinson and Olson titled “Mosquito Management and Control.”
Because horses show symptoms quicker than humans, they can act as sentinels for EEE activity in an area, Robinson noted.
Symptoms in horses include fever, irregular gain, wandering, circling, incoordination, yawning, grinding of teeth, pendulous lower lip, the inability to swallow, paralysis and occasional convulsions.
In humans, the symptoms include fever, headache, vomiting, lethargy, neck stiffness and coma.
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