Mosquitoes and West Nile Virus

West Nile Virus Questions & Answers

 What is West Nile virus?

West Nile virus can be a serious, even fatal, illness. It can affect people, horses, certain types of birds, and other animals. In 1999, West Nile virus first appeared in the United States in New York City. Since that time, it has spread rapidly throughout the country. In Washington, the first cases of people becoming ill from West Nile virus were reported in 2006.

For an overview of West Nile virus, visit the Centers for Disease and Prevention,

How is it spread?

West Nile virus is almost always spread to people by the bite of an infected mosquito. Mosquitoes become infected after feeding on birds that carry the virus. There is no evidence that West Nile virus can be spread by direct contact with infected people or animals. 

Who is at risk?

The risk of getting West Nile virus is very low, but anyone can become infected. People over 50 years of age have the highest risk of serious illness.

What are the symptoms?

Most people who are infected with West Nile virus will not get sick. About 1 in 5 people infected will have mild symptoms such as fever, headache, and body aches. Even fewer, about 1 in 150 people infected, will have more severe symptoms. Severe symptoms may include headache, high fever, neck stiffness, stupor, disorientation, tremors, convulsions, muscle weakness, paralysis, and coma. If you have any of these symptoms, contact your health care provider. 

Preventing West Nile Virus

Prevention is the key to minimizing the risk of exposure to WNV. Everyone should take action to minimize the risk:

·  Reduce mosquito larvae habitat around the home by dumping standing water.

·  Change water in birdbaths, fountains, wading pools, animal troughs, and other sources once or twice a week.

·  Stay indoors when mosquitoes are most active (dusk to dawn).

·  Make sure the screens on doors and windows are working properly.

·  Cover exposed skin with light colored clothing when outside in the evening.

·  Use an effective repellent on exposed skin and always follow the directions on the label.