Symptoms

• Most people have no symptoms. Most people who are infected with the West Nile Virus will not experience any type of illness or even know they are infected.
• Some people experience relatively mild symptoms. It is estimated that 20% of the people who become infected will develop mild to severe illness, sometimes called West Nile fever, or West Nile non-Neurological Syndrome (WNnonNS). The symptoms of this flu-like illness include:
  • Fever
  • Headache (sometimes severe and long-lasting)
  • Body aches
  • Swollen lymph glands
  • Skin rash on the trunk of the body (occasionally)
• Some people (about 1 in 150 people infected with WNv) will experience the severe illness known as West Nile Neurological Syndrome (WNNS), which can sometimes be fatal. The signs and symptoms include:
  • Headache
  • High fever
  • Neck stiffness
  • Stupor
  • Disorientation
  • Coma
  • Tremors
  • Convulsions
  • Muscle weakness
  • Paralysis

People over the age of 50 are more likely to develop serious symptoms if they do get sick from a WNv infection. Illness most often occurs in people between the ages of 40 and 59, with the median age of 50.