West Nile Virus

West Nile Virus

Public Health Fact Sheet

What is West Nile Virus (WNV)?
West Nile Virus (WNV) is a mosquito-borne virus that causes an infection that results in swelling of the brain. Fortunately, most people infected with WNV do not feel sick. About 1 in 5 people who are infected develop a fever and other symptoms. About 1 out of 150 infected people develop a serious, sometimes fatal, illness.

How is West Nile Virus spread?
Mosquitos become infected when they feed on infected birds. Infected mosquitos then spread West Nile Virus to people and other animals by biting them.

How is West Nile Virus treated?
There is no vaccine or specific treatment for West Nile Virus. Over-the-counter pain medication can be used to reduce fever and relieve some symptoms. In severe cases, patients often need to be hospitalized to receive supportive treatment. If you think you or a family member might have West Nile Virus disease, talk with your health care provider.

How can West Nile Virus be prevented?
The most effective way to prevent infection from West Nile Virus is to prevent mosquito bites. Limit evening outdoor activities when mosquitos are most active. Use insect repellent (20% - 30% DEET work best), wear long-sleeved shirts and pants, treat clothing and gear, and take steps to control mosquitos indoors and outdoors.

Additional information is available on the CDC website at www.cdc.gov/westnile/
Symptoms of West Nile Virus
  • Headache
  • Stiff neck
  • Disorientation
  • Body aches
  • Skin rash
  • Swollen lymph glands
  • Paralysis

February 2020