Most people infected with West Nile virus will not become ill. Among those who have symptoms, the disease tends to resemble flu. Symptoms may include:

Sometimes the virus causes an inflammation of the brain (encephalitis) or its lining (meningitis). People can become very ill, or even die. Symptoms may include:

Anyone who has these symptoms, or long-lasting flu symptoms, should seek medical care immediately. Blood tests can reveal whether West Nile virus is present.

Currently, there is no vaccine against West Nile for use in people. Nor is there a specific treatment.

Health care professionals can provide "supportive" care to help your body get through the illness. In severe cases, this treatment can include: