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Dunn County Horse Tests Positive for Eastern Equine Encephalitis Virus

Protect yourself against mosquito bites

Menomonie – The Dunn County Health Department reports that two horses in Dunn County have tested positive for eastern equine encephalitis (EEE), which is caused by the EEE virus. This is the first documented EEE activity in the state this year. No EEE cases in humans have been reported in Wisconsin thus far in 2020. Only three human cases of EEE have been reported in Wisconsin between 1964 and 2017.

EEE virus is spread to humans, horses, and other animals through the bite of an infected mosquito. Mosquitoes acquire EEE virus by feeding on infected birds. The virus is not spread person to person or directly between animals or between animals and humans. Presence of a EEE positive horse confirms that there are mosquitoes in the area infected with the EEE virus that can spread the virus to people and other animals.

Many people infected with EEE virus do not get sick. Those who do become ill may develop encephalitis (inflammation of the brain) that typically begins with the sudden development of fever, headache, chills, and vomiting. The illness may become severe resulting in disorientation, seizures, coma, or death. There is no specific treatment for EEE illness.

Signs of EEE infection in horses include depression, loss of appetite, drooping eyelids and lower lip, blindness, paralysis, and death. Horse owners can vaccinate their horses against EEE virus to protect them from becoming ill.

Because EEE virus is known to be circulating in Dunn County, residents and visitors to are should be vigilant in preventing mosquito bites. The Dunn County Health Department offers these tips to protect yourself and your family against mosquito bites:
•Limit time spent outside at dawn and dusk, when mosquitoes are most active.
• Apply an insect repellant with DEET, IR3535, picaridin, or oil of lemon eucalyptus to exposed skin and clothing.
•Make sure window and door screens are in good repair to prevent mosquito entry.
•Prevent mosquitoes from breeding by removing stagnant water from items around your property, such as tin cans, plastic containers, flower pots, discarded tires, roof gutters, and downspouts.
•Turn over wheelbarrows, wading pools, boats, and canoes when not in use.
•Change the water in bird baths and pet dishes at least every three days.
•Clean and chlorinate swimming pools, outdoor saunas, and hot tubs; drain water from pool covers.
•Landscape to prevent water from pooling in low-lying areas, and trim tall grass, weeds, and vines since mosquitoes use these areas to rest during hot daylight hours.

For more information about EEE virus, please visit:

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