The West Nile Virus (WNV) is a mosquito-borne virus that can cause a mild fever to encephalitis (swelling of the brain) or meningitis (swelling of the membranes surrounding the brain and spinal cord) in humans and other mammals.

The virus is transmitted to humans, horses and other mammals and birds by the bite of an infected mosquito, most commonly stagnant water species (Culex pipiens).

The virus cycle is maintained in nature between mosquitoes and birds, the latter serving as reservoir hosts. The mosquito becomes infected by biting a bird that carries the virus. An infected mosquito can also spread the virus to a healthy bird. Overwintering adult Culex mosquitoes can harbor the virus and thereby serve as one way of sustaining the disease year to year.

WNV is not normally transmitted person-to-person in the absence of any exchange of blood. Normally, WNV is not contracted from contact with infected birds, but rare cases have been documented of lab workers being infected through breaks in the skin from infected bird blood. As a precaution, everyone who handles dead birds should wear gloves.

Ways to reduce your risk of being infected

1.  Avoid outdoor activities between dusk and dawn when mosquitoes are likely to be biting.

2.  If you must be outdoors when mosquitoes are active, cover up by wearing shoes, socks, long pants and long-sleeved shirts.

3.  Apply mosquito repellent to exposed skin or on clothing. An effective repellant will contain DEET (N, N-diethyl-m-tolumide) as an active ingredient. Follow directions on the label for use, and take special precautions for children. Other repellents are less effective as studies have proved. Ultrasonic devices, "bug zappers," and purple martins are not effective in preventing mosquito bites.

4.  Maintain screening on windows and doors to keep mosquitoes out of buildings.

Eliminate mosquito breeding sites

1.  Remove all discarded tires from your property.

2.  Empty standing water from buckets, tin cans, plastic containers, flower pots, or similar water-holding containers.

3.  Make sure roof gutters drain properly, clean clogged gutters in the spring and fall.

4.  Clean and chlorinate swimming pools and hot tubs. If not in use, keep empty and covered.

5.  Change the water in bird baths at least once a week.

6.  Turn over plastic wading pools, and wheelbarrows, etc. when not in use.

7.  Eliminate any standing water that collects on your property.

8.  Encourage neighbors to eliminate breeding sites on their properties.

9.  Alert health authorities to potential breeding sites in your area.