Nile virus (WNV) is a serious illness that can affect people, horses, certain types of birds, and other animals.
West Nile virus is transmitted by mosquitoes, however, less than 1% of mosquitoes are infected with the virus. Of the
people who get infected, less than 1% develop a severe illness, which can sometimes be fatal.
In 1999, WNV first appeared in the U.S. in New York. Since that time, it has spread rapidly throughout the country. In 2002, the virus was found for the first time
in birds and horses in Washington. In 2008 there were three human cases in the state, one in King County and two in Yakima County. There were also 41 horses in
eastern Washington that contracted the disease. Dead birds in Thurston, Lewis, Pierce, and King counties
tested positive for the virus. It is very likely that Washington will see more humans, horses, and birds with the disease in 2009.
West Nile virus is transmitted to humans through mosquito bites. Mosquitoes become infected when they feed on infected
birds that have high levels of WNV in their blood. Infected mosquitoes can then transmit WNV when they feed on humans or other animals.
How to avoid mosquito bites, what are the most effective mosquito repellents, and how to reduce places where mosquitoes live and breed around your home.
Reporting Dead Birds
We are currently seeking information from citizens about the location, species, and numbers of dead birds in Thurston
County. Find out more about reporting procedures. ...more
Some of the most frequently asked questions about West Nile virus....more
Information on choosing repellents, their effectiveness, and using them safely. ...more
Info for Veterinarians & Health Care Providers
Clinical and reporting information for veterinarians and health care providers from the WA Dept of Health.
- Washington Department of Health - Includes the
latest WNV information in Washington, including basics about the disease, surveillance efforts in Washington State, related health issues, and educational materials.
- Centers for Disease Control and Prevention -
Includes West Nile virus basics, maps of WNV activity in the U.S., preventative measures, and other resources. NOTE: This information is offered in several languages.
- National Wildlife Health Center - West Nile virus
information from the U.S. Geological Survey with a focus on U.S. wildlife.