Sunday, November 19, 2017
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What is West Nile Virus?

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. Fortunately, most people infected with WNV will have no symptoms. About 1 in 5 people who are infected will develop a fever with other symptoms. Less than 1% of infected people develop a serious, sometimes fatal, neurologic illness.The disease was first observed in Uganda in the late 1940's. It first entered the U.S. in 1999 in New York City. It entered the state of Missouri in 2001 and has since become endemic. The disease causes sporadicwide spread outbreaks which can not be predicted but usually accompany hot dry weather patterns. The virus is maintained within an ecosystem by birds and small mammals and is spread by mosquitoes. The risk of coming into contact with mosquitoes infected with the West Nile Virus in Jefferson County Missouri has remained at or above a moderate level since it first entered the State of Missouri. 

What can you do to protect yourself?

Elimination of man-made standing water sources is the best way to eliminate the species of mosquitoes that carry the virus. Any container item capable of holding water for seven days or more should be removed, altered or inverted. Examples of the types of breeding sources include but are not limited to: aluminum cans, buckets, swimming or wading pools, tarps, flower pot sill plates, clogged gutters, food packaging, wheel barrows, bird baths, tires, bottle caps, or any man made item that are capable of holding water. 

The mosquito species that transmits the West Nile Virus is typically active from dusk to dawn. When outside at any time or in areas where mosquitoes are active the best defense against mosquitoes is to use insect repellents that contain DEET, Picaridin or Oil of Eucalyptus. Don't apply repellants that contain permethrin to bare skin. These are meant to be applied to clothing only. If weather permits use of long sleeves and long pants is advised. 

More information can be found about West Nile at the CDC West Nile Information Page.

Interactive map of United States with West Nile Distribution.

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