How serious is the illness caused by West Nile virus?
Illness related to mosquito bites is rare. However, you should see a doctor immediately if you develop symptoms such as high fever, confusion, muscle weakness, severe headaches, stiff neck or if your eyes become sensitive to light. WNV affects the central nervous system and can be very serious. Some people who get infected with WNV develop a paralysis or an inflammation of the brain known as encephalitis. These severe diseases usually require hospitalization. Symptoms may last several weeks and some effects may be permanent. Patients with mild symptoms should recover completely, and do not require any specific medication or laboratory testing.