Juneau County Horse Tests Positive for Eastern Equine Encephalitis

by Juneau County Health Department

Mauston - The Juneau County Health Department reports that a horse in Juneau County has tested positive for Eastern equine encephalitis (EEE) which is caused by the EEE virus. The EEE virus is transmitted by mosquitoes. The Wisconsin Department of Agriculture, Trade and Consumer Protection reported the positive test result to the Wisconsin Division of Public Health. No EEE cases in humans have been reported in Wisconsin this year or any year since 2011. The human EEE case in 2011 was only the second case known to have occurred in Wisconsin since 1984.

EEE virus is transmitted to humans, horses, birds, and other animals during bites from infected mosquitoes. Mosquitoes acquire EEE virus by feeding on infected birds. The virus is not transmitted 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 transmit the virus to people and other animals.

Most people infected with EEE virus do not have symptoms. However, some infected people develop encephalitis (inflammation of the brain) that typically begins with sudden onset of fever, headache, chills, and vomiting. The illness may become severe resulting in disorientation, seizures, coma, or death. There is no specific treatment for this EEE illness.

Clinical 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 currently circulating, Wisconsin residents and visitors to the state should be vigilant in taking measures to prevent mosquito bites. It is important that people contact their healthcare provider if they suspect they have EEE illness.

The best way to avoid mosquito-borne diseases is to reduce exposure to mosquitoes and eliminate mosquito breeding sites. When cold weather arrives, the mosquitoes will be eliminated, but until then people are urged to take measures to protect themselves.

The Juneau County Health Department recommends the following:

Limit time spent outside at dawn and dusk, when mosquitoes are most active.

Apply insect repellant to clothing as well as exposed skin since mosquitoes may bite through clothing.

Make sure window and door screens are in good repair to prevent mosquito entry.

Properly dispose of items that hold water, such as tin cans, plastic containers, ceramic pots, or discarded tires.

Clean roof gutters and downspouts for proper drainage.

Turn over wheelbarrows, wading pools, boats, and canoes 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 tall grass, weeds, and vines since mosquitoes use these areas to rest during hot daylight hours.

Landscape to prevent water from pooling in low-lying areas.

For more information about EEE virus, please visit: