About West Nile

Key points

  • West Nile virus is most commonly spread through the bite of an infected mosquito.
  • Symptoms include fever, headache, body aches, vomiting, diarrhea, or rash.
  • There are no vaccines to prevent or medicines to treat West Nile virus disease (West Nile) in people.
  • You can reduce your risk by taking steps to prevent mosquito bites.
Mosquito that spreads West Nile virus on a persons arm.

Overview

West Nile virus is the leading cause of mosquito-borne disease in the continental United States. It is most commonly spread to people by the bite of an infected mosquito. Cases of West Nile occur during mosquito season, which starts in the summer and continues through fall.

There are no vaccines to prevent or medicines to treat West Nile in people. Fortunately, most people infected with West Nile virus 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. Reduce your risk of West Nile by preventing mosquito bites.

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Content Source:
National Center for Emerging and Zoonotic Infectious Diseases (NCEZID)