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West Nile Virus

Disease Information

West Nile virus (WNV) is carried by mosquitoes and can infect humans, horses, and birds. Humans can only get the virus from the bite of an infected mosquito; the disease does not spread from other animals to humans, or from person to person.

Most infections are mild, with fever and flu-like symptoms, but severe infections may cause encephalitis (inflammation of the brain), and rarely, death.

To prevent WNV

  • Avoid mosquito bites.
  • Mosquito-proof your home by draining standing water where mosquitoes breed.
  • Help your community by reporting sick or dead birds to reduce your risk for becoming sick.

Oregon Health Authority, Public Health Division works with local health departments, mosquito control districts and other agencies to detect and test for the presence of WNV.

Learn more

Disease Reporting

What is required?

Health Care Providers, Clinical Laboratories and Veterinarians

Health care providers and clinical laboratories are required by law to report cases and suspect cases of West Nile virus. Veterinarians are required to report horses with the appropriate clinical signs.

For Local Health Departments


Once you click on the Tableau link, you will be able to select your disease of interest.

See Also

CDC Factsheet