| West Nile Encephalitis |
{wnv birds mosquitoes pic} |
Frequently Asked Questions
What is West Nile encephalitis?
West Nile encephalitis (WNE) is an infection of the brain caused by West Nile virus (WNV), a flavivirus found in Africa, Eastern Europe, and West Asia, which is closely related to St. Louis encephalitis virus found in the United States and to Kunjin virus, which is found in Australia, some Western Pacific islands, and parts of South East Asia.
How do people get WNE?
Most commonly by the bite of a mosquito that is infected with WNV. However, a number of cases are suspected to be transmitted through blood transfusions, organ donation, breast milk, and through hand cuts in lab workers handling infected birds.
What can I do to reduce my risk of contracting WNE?
Remove or clean up any mosquito-breeding sites on your property.
Be sure your window screens are in good condition.
Stay indoors at dawn, dusk, and in the early evening during mosquito active periods (Usually April – October).
Wear long-sleeved shirts and long pants whenever you are outdoors.
Apply insect repellent sparingly to exposed skin.
Spray clothing with repellents containing permethrin or DEET, as mosquitoes may bite through thin clothing. Whenever you use an insecticide or insect repellent, be sure to read and follow the manufacturer's directions for use.
Do not handle dead or sick birds directly. Use gloves or a long handled shovel and bury them if not accepted for lab testing. Otherwise use double or triple plastic bags and seal with a twist-tie before transporting.
What do I do if I find a dead bird? Dead bird sightings can be reported
here.
Where can I get more information on pesticides used to control mosquitoes? Visit the Environmental Protection Agency (EPA) website on
Pesticides and Mosquito Control
Does Pennsylvania have an effective mosquito surveillance and abatement program? Pennsylvania, initiated a WNV mosquito surveillance and control program in the Spring of 2000. In Chester County, this includes mosquito trapping, identification of mosquito breeding areas, and control of mosquitoes at the larval stage. Currently, ground-level adulticide sprays are used in specific local areas where heavy mosquito breeding and adult mosquito populations are identified.
What about ticks? Since ticks have been found infected with WNV in other countries, CDC is also testing ticks for WNV in outbreak areas. A tick-borne encephalitis virus (TEV, a.k.a. Powassan virus) has been found in ticks in Canada and in some New England states.
Can other animals get sick? Yes. Cats, crows and horses have tested positive for WNV. In addition, dogs, many other species of wild and domestic birds (chickens, ducks, geese and turkeys) while not clinically ill were tested and shown to be positive for WNV.
Should a dog or cat infected with WNE be destroyed? No. There is no reason to destroy an animal just because it has been infected with WNE. Full recovery from the infection is likely.
What are the signs of WNE in a horse? In a small number of horses the virus can cause encephalitis, which may kill the animal. Clinical signs may include one or more of the following; loss of appetite, depression, fever, weakness of hind legs, paralysis, impaired vision, ataxia, head pressing or head tilt, aimless wandering, convulsions, inability to swallow, circling, hyperexcitability, or coma.. Visit the
Penn State Extension site for more information on horses and WNV.
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