Theresia Lavergne, Merrill, Thomas A. | 10/4/2004 4:25:43 AM
Dr. Theresia K. Lavergne, a poultry science specialist with the LSU AgCenter, says concern about problems with West Nile Virus, Eastern Equine Encephalitis and Western Equine Encephalitis always increases during the summer – when mosquito populations generally are up and more cases are reported.
But Lavergne also says the incidence of these viruses in chickens, turkeys, ducks, pheasants, chukars, ostriches and emus in Louisiana are relatively limited. Natural immunity in chickens and turkeys protects them from West Nile, and a vaccine is available to protect domestic poultry from Eastern Equine Encephalitis.
"There is no animal-to-animal, animal-to-person or person-to-person transmission of the encephalitis viruses," Lavergne explains. "Thus, people cannot be infected by touching and caring for other people or animals that have the disease.
"The only mode of transfer of West Nile Virus, Eastern Equine Encephalitis or Western Equine Encephalitis is through infected mosquitoes, and only a small number of certain species of mosquitoes carry the viruses. The viruses are transferred when mosquitoes bite an infected wild bird, and then the same mosquito must bite a person or animal to transfer the virus."
West Nile Virus, Eastern Equine Encephalitis and Western Equine Encephalitis are types of encephalitis, or inflammation of the brain, caused by the individual viruses.
"Since West Nile Virus, Eastern Equine Encephalitis and Western Equine Encephalitis infect wild birds such as crows and blue jays, I am frequently asked if poultry such as chickens and turkeys can become infected," Lavergne said. "The answer is that the chances are very unlikely."
Lavergne said chickens and turkeys can develop antibodies to WNV. "Therefore, any infection chickens or turkeys may sustain would be very mild and brief – and very unlikely to infect mosquitoes," she said.
In addition, the LSU AgCenter expert said Eastern Equine Encephalitis is rarely diagnosed in confinement-reared domestic poultry. While she cautions that chickens, turkeys, ducks, pheasants, chukars and ratites (ostrich and emu) are susceptible to this virus, she also adds that there is a vaccine available for domestic poultry.
"Furthermore, since the majority of Western Equine Encephalitis cases occur in the central and western plains of the United States, it is unlikely that chickens and turkeys in Louisiana will be infected with that virus," Lavergne said.
Although the chances of your poultry being infected with these viruses are low in Louisiana, Lavergne and other LSU AgCenter experts stress it is still important to take precautions that will protect your poultry and yourself.
"Cases of encephalitis usually occur in the hot weather of late summer to early fall, but mosquitoes can be active all year in Louisiana," Lavergne said. "Therefore, we should take precautions all year."
Among the suggested precautions are to reduce the number of mosquitoes around your home and neighborhood.
"The number of mosquitoes can be reduced by reducing the amount of standing water available for mosquito breeding," Lavergne said.
This is done by disposing of all water-holding containers (including discarded tires); cleaning clogged roof gutters; emptying water from wheelbarrows, boats, trailers, toys and pots; turning over plastic wading pools when not in use; not allowing water to stagnate in bird baths, ornamental pools, water gardens and swimming pools or their covers; and by altering the landscape of your property to eliminate standing water.
In addition, to protect yourself from being bitten by mosquitoes, you can stay inside at dawn, dusk and in the early evening; make sure window and door screens are "bug-tight"; use the proper type of lighting outside; wear long-sleeved shirts and long pants; use electric fans at outdoor events; and use insect repellents.
"It is unlikely that your poultry will become infected with West Nile Virus, Eastern Equine Encephalitis or Western Equine Encephalitis," Lavergne said. "And the chance of infection can be reduced even more with the implementation of measures to reduce mosquito populations.
"On the other hand, if you do find a dead wild bird that may be infected with any of these viruses, report it to your parish health unit’s Environmental Heath Services office."