West Nile virus (WNV) causes a potentially serious illness related to Japanese Encephalitis (JE) and Saint Louis encephalitis (SLE). The virus survives in nature in birds and is transmitted by mosquitoes that feed on infected birds (click on image). When humans and other mammals, such as horses, are bitten by infected mosquitoes they may also become infected with WNV. Most persons who become infected with the virus will not become ill. However, for the small proportion who do become sick, symptoms can include fever, headache, rash, muscle weakness, and nausea and vomiting. A smaller proportion may develop neurological symptoms such as limb paralysis, tremors, and altered mental status.
Before 1999, when it was detected in New York City, WNV was found in Africa, Asia, Europe, Middle East, and Australia. Since then, the virus has spread throughout the United States as well as other parts of North America. In 2014, 2,205 confirmed human WNV cases were reported nationally to the Centers for Disease Control and Prevention (CDC); California (CA) reported 801 cases.
|West Nile Virus Activity in Kern County (Updated 10/30/2015)|
WNV Strategic Response Plan