Indiana Eastern Equine Encephalitis EEE virus in horses

INDIANAPOLIS — State health officials are warning people about a rare mosquito-borne virus that is killing about a third of those infected.

Eastern equine encephalitis (EEE) virus, often referred to as “sleeping sickness” in horses, is a rare mosquito-borne virus that can infect both humans and horses. The Indiana Department of Health is warning people to protect themselves and monitor their horses following confirmed cases in northern Indiana.

As of Oct. 4, two horses in LaGrange County and one horse in Kosciusko County tested positive for the EEE virus in 2022. No human cases have been reported for the year so far, according to the department.

“EEE virus (“Triple E”) is a serious threat to horses and humans in northern Indiana,” said Dr. Bret Marsh, DVM, State Veterinarian with the Indiana State Board of Animal Health. “While this risk is currently decreasing due to cooler weather, it will remain until the first hard freeze of the year.”

Although no human cases have been reported this year, the virus can cause serious illness, with a mortality rate of about 33 percent or more. Even if patients recover, they can suffer from long-term complications.

Symptoms of EEE virus disease include chills, fever, and body and joint pain. Some people develop a more severe form of the disease that affects the nervous system and causes inflammation of the brain.

In horses, the virus causes listlessness, high fever, head strain and seizures. It’s called “sleeping sickness” because infected animals become comatose. Horses that develop EEE rarely survive.

While the risk of EEE virus infection begins to fall as evening and nighttime temperatures drop to 60F, the department says the risk won’t be eliminated until the first hard overnight freeze. State officials recommend the following preventative measures for vulnerable individuals:

• Avoid being outdoors when mosquitoes are active (especially late afternoon, dusk to dawn, and early morning).
• Use an EPA-registered insect repellent that contains DEET, picaridin, IR3535, lemon eucalyptus oil, or 2-undecanone on clothing and exposed skin
• Cover exposed skin by wearing a hat, long sleeves, and long pants in places where mosquitoes are particularly active, such as B. in wooded areas
• Install or repair screens on windows and doors to keep mosquitoes out of your home
• Vaccinate horses against EEE annually according to the guidelines of the American Association of Equine Practitioners

How to eliminate mosquito breeding grounds from your property:

• Discard old tires, tin cans, ceramic pots, or other containers that can hold water
• Repair failed septic systems
• Drill holes in the bottom of outdoor recycling bins
• Keep the grass cut short and the bushes trimmed
• Clear clogged gutters, especially when leaves tend to clog the drains
• Replace the water in pet bowls frequently
• Flush ornamental fountains and bird baths regularly
• Aerate ornamental tanks or stock them with predatory fish