Three people in Tennessee have tested positive for West Nile virus as of Thursday afternoon, according to the Tennessee Department of Health.

Eliminate standing water in your yard. Mosquitoes breed in pools of standing water. Unclog roof gutters. Empty unused swimming pools. Change water in birdbaths at least weekly. Remove old tires or any unused containers that might hold water and serve as a breeding place for mosquitoes. To reduce your own exposure to mosquitoes: Avoid unnecessary outdoor activity when mosquitoes are most prevalent, such as at dawn, dusk and early evening. Wear long-sleeved shirts and long pants when you go into mosquito-infested areas. Apply mosquito repellent containing an Environmental Protection Agency-registered insect repellent to your skin and clothing. Choose the concentration based on the hours of protection you need — the higher the percentage (concentration) of the active ingredient, the longer the repellent will work. Follow the directions on the package, paying special attention to recommendations for use on children. When outside, cover your infant's stroller or playpen with mosquito netting.

Kids and adults younger than 50 are less likely to become sick from the infection if they do get it.

West Nile virus is one of several mosquito-borne viruses in the United States that can infect people. The virus exists in nature primarily through a transmission cycle involving mosquitoes and birds. Mosquitoes become infected with West Nile virus (WNV) when they feed on infected birds. Click here to go to the West Nile Virus Home Page.

West Nile virus (WNV) is most commonly transmitted to humans by mosquitoes.

You can reduce your risk of being infected with WNV by using insect repellent and wearing protective clothing to prevent mosquito bites. There are no medications to treat or vaccines to prevent WNV infection.

Less than 1% of infected people develop a serious, sometimes fatal, neurologic illness.

About 1 in 5 people who are infected will develop a fever with other symptoms such as headache, body aches, joint pains, vomiting, diarrhea, or rash. Most people with this type of West Nile virus disease recover completely, but fatigue and weakness can last for weeks or months.

Over-the-counter pain relievers can be used to reduce fever and relieve some symptoms

In severe cases, patients often need to be hospitalized to receive supportive treatment, such as intravenous fluids, pain medication, and nursing care.

"Looking at the risk of getting infected, anyone who is outdoors and participating in activities is,'' says Erin Staples, MD, PhD, medical epidemiologist at the CDC.

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