Clark County Horse Tests Positive for EEE Virus

Tuesday, October 26th, 2021 -- 2:00 PM

The Clark County Health Department reports that a horse in Clark County has tested positive for eastern equine encephalitis, which is caused by the EEE virus.

This is the first confirmed case of EEE in a horse in Clark County this year, and the tenth case in horses in the state this year. No EEE cases in humans have been reported in Wisconsin thus far in 2021. However, there were two human cases in 2020.

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.

Documentation of a EEE positive horse, however, confirms 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 fever, headache, chills, and vomiting. The illness may become severe resulting in encephalitis (inflammation of the brain), disorientation, seizures, coma, or death. There is no specific vaccine or treatment for EEE illness available for people.

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.

Since EEE virus is known to be circulating in Clark County, and since mosquitoes can remain active until the first hard frost (temperatures below 28 degrees for at least four consecutive hours), it’s encouraged for residents and visitors to be cautious in preventing mosquito bites.

The Clark County Health Department recommends you follow these tips to protect yourself and your family against mosquito bites. Apply an insect repellent with DEET, picaridin, oil of lemon eucalyptus, or IR3535 to exposed skin and clothing.

Prior to heading outdoors, treat clothing with permethrin; do not apply permethrin directly to skin. Consider rescheduling outdoor activities that occur during evening or early morning hours, when mosquitoes are most active.

Wear long sleeves, long pants, and socks when outdoors to help keep mosquitoes away from your skin. Make sure window and door screens are intact and tightly fitted to prevent mosquitoes from getting into your home.

Prevent mosquitoes from breeding around your home 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, kiddie pools, buckets, and small boats such as canoes and kayaks when not in use. Change the water in birdbaths and pet dishes at least every three days.

Clean and chlorinate swimming pools, outdoor saunas, and hot tubs; drain water from pool covers. Trim or mow tall grass, weeds, and vines since mosquitoes use these areas to rest during hot daylight hours.

Feel free to contact us with questions and/or comments.