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For Immediate Release
August 19, 2021
Elizabeth Goodsitt, 608-266-1683
Jennifer Miller, 608-266-1683

Health Department Urges People to Keep Taking Steps To Avoid Mosquito-Related Illnesses

Four cases of Eastern equine encephalitis have been found in Wisconsin horses

As summer winds down and the risk for some illnesses spread by mosquitoes goes up, health officials are encouraging Wisconsin residents to use simple prevention steps to Fight the Bite.

On average, 44 human cases of illnesses spread by mosquitoes in Wisconsin are reported to public health each year. Since many infections cause mild illness that goes undiagnosed, the actual number of Wisconsin cases is likely to be much higher.

Mosquito-related illnesses can also affect animals. Recently, the first Eastern equine encephalitis (EEE) activity this year was reported in four horses, one each in Monroe, Burnett, Calumet and Marquette counties. EEE is spread through the bite of a mosquito carrying the virus, which mosquitoes can get after biting an infected bird. While horses can’t spread EEE directly to humans or even to mosquitoes that bite them, a case of EEE in a horse confirms that some mosquitoes in the area are infected with the virus and may spread EEE to people and other animals.

Symptoms of EEE in humans include the sudden onset of fever, chills, and body and joint aches. EEE infection can develop into severe encephalitis, resulting in headache, disorientation, tremors, seizures, and paralysis. Permanent brain damage, coma, and death may also occur in some cases. These symptoms are similar to those caused by West Nile virus (WNV) another illness spread by mosquitoes that is most commonly spread during late summer, though WNV is less likely to cause severe illness or death. There have not yet been any cases of WNV reported in horses or humans so far in 2021.

Taking these simple steps can help protect you and your family from getting these diseases:

  • Use an EPA-registered repellent, such as DEET, picaridin, oil of lemon eucalyptus, or IR3535 and apply according to label instructions.
  • Use permethrin-treated clothing and gear.
  • Wear loose-fitting long-sleeved shirts and long pants to keep mosquitoes away from your skin.
  • Avoid spending time outdoors at dawn and dusk when mosquitoes are most active.
  • Take steps to control mosquitoes outside your home.

Because the viruses follow mosquito populations, the threat in Wisconsin varies depending on the weather, but normally starts in mid- to late summer and remains until the first killing frost (temperatures below 32 degrees for at least three hours).

More information on how to fight the bite is available on the Department of Health Services (DHS) website. Information on Eastern equine encephalitis is available on the DHS website and on the Department of Agriculture, Trade, and Consumer Protection website.

Last revised October 13, 2021