What are the symptoms of West Nile encephalitis in humans?
WNV affects the central nervous system. Symptoms may vary. Approximately 80% of people who are infected with WNV will not show any symptoms at all. Up to 20% of the people who become infected will display mild symptoms, including fever, headache, body ache, nausea, vomiting and sometimes swollen lymph glands or a skin rash on the chest, stomach and back. Symptoms typically last a few days. About one in 150 people infected with WNV will develop severe illness. The 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.
