West Nile Virus

West Nile virus is a “bird virus” that is primarily transmitted between birds by mosquitoes. The virus is transmitted to humans through the bite of a mosquito infected with West Nile virus. People who get West Nile virus cannot transmit it to other people.


The virus is a mosquito-borne disease that was originally found in Africa. In 1999, it was detected in the eastern United States; since then the virus has spread throughout the United States and is well established in most states. In 2003, the virus was first confirmed in California.

Today, West Nile virus is considered endemic, which means we can expect the virus to stay in our environment. To get the latest West Nile virus statistics, click HERE.

One in five persons infected with West Nile virus will exhibit symptoms. Symptoms usually occur between five and 15 days, and can include fever, headache, body aches, nausea, or a skin rash. These symptoms can last for several weeks to months. One in 150 people infected with the virus will become severely ill. Severe symptoms include high fever, muscle weakness, neck stiffness, coma, paralysis, and possibly death.

Does your city/community have confirmed virus activity? Find out HERE.