West Nile Virus Infection

West Nile Virus is a mosquito transmitted virus that can cause illness in humans. Mosquitoes become infected with the virus when they feed on infected birds. The virus was first identified in the United States in 1999, but has been circulating throughout Africa, Europe, the Middle East, and Asia since 1937. West Nile Virus was first identified in infected wild birds in Wisconsin in 2001, and the first human infections in Wisconsin were seen in 2002. Douglas County had its first and only case of human West Nile Infection in 2003, but infected birds have been detected in subsequent years.

Dead Bird Reporting
The Wisconsin State Department of Health Services conducts testing on dead crows, blue jays, and ravens to track the spread of the West Nile Virus.  To report a dead bird and determine if it is eligible for testing, please call the Dead Bird Reporting Hotline at 1-800-433-1610.  You will be given instructions on how to submit the bird for testing, if it is eligible.  Do not handle the bird with your bare hands.

Who Can Become Infected
Anyone can become infected with West Nile Virus, but adults over age 50 are more likely to develop severe disease. About 80 percent of people infected do not have any symptoms. Of the remaining 20 percent, most develop a mild illness, but some people (less than one percent of those infected) can go on to develop West Nile Encephalitis, a severe disease. 

Prevent Infection

There is no specific treatment for West Nile Virus infection. The best way to prevent infection is to prevent mosquito bites, including the following personal protective measures:

  • Limit Exposure – Limit the time spent outside during mosquito season (June – September), especially at dawn and dusk when mosquitoes are more active.
  • Cover Up – Wear socks, shoes, long sleeve shirts, and long pants when outdoors, if possible.
  • Spray – Apply insect repellants containing an EPA registered ingredient, such as DEET, to exposed skin when outdoors.
  • Drain Water – Mosquitoes lay their eggs in standing water, so look around for possible mosquito breeding sites around your home. A few ideas: empty buckets, change the water in birdbaths regularly, turn over wheelbarrows when not in use. Encourage your neighbors to do the same!
Information and statistics on West Nile Virus in Wisconsin can be found at the following:
Additional Information
For more information on West Nile Virus, feel free to contact:
Douglas County Department of Health & Human Services
Phone:  (715) 395-1304