Symptoms of WNV
People typically develop symptoms of West Nile virus between three and 14 days after they are bitten by an infected mosquito.
About 80 percent of people, four out of five, who are infected with WNV will not show any symptoms.
Mild to Moderate Symptoms
Up to 20 percent, about one in five, of people who become infected will display symptoms which can include fever, headache, body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach and back. Symptoms generally last for just a few days, although even previously healthy people can become seriously ill.
About one in 150 people infected with WNV will develop severe illness. Severe symptoms can include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis. These symptoms may last several weeks and neurological effects may be permanent. WNV can be fatal.
People over 50 are at higher risk for severe illness and serious symptoms of WNV. The more time you’re outdoors, the greater potential for mosquito bites and increased West Nile virus risk.
There is no specific treatment for WNV. In cases with mild symptoms, people can usually recover at home. In more severe cases, people may need hospitalization and supportive treatment including intravenous fluids to help with breathing and nursing care.
If you develop symptoms of WNV illness, such as unusually severe headaches or confusion, seek appropriate medical attention.