Deer Tests Positive For EEE Virus In Lisbon

LISBON, CT — A white-tailed deer that exhibited neurologic symptoms and died Aug. 12 in Lisbon was infected with the eastern equine encephalitis (EEE) virus, according to a statement from the Department of Energy & Environmental Protection (DEEP).

A University of Connecticut lab conducted a necropsy and tested the deer for various illnesses, determining that the EEE virus resulted in the deer's neurologic symptoms.

EEE is a serious but rare illness caused by a virus transmitted by mosquitoes. It is the most severe mosquito-transmitted disease in the U.S., with about 40 percent mortality and significant brain damage in half of survivors.

The last major outbreak of EEE occurred in 2019, involving 38 human cases nationally with 19 cases occurring in New England.

No human or horse cases of EEE have been reported in Connecticut this year, although human cases have been documented in Massachusetts, Vermont, and New Jersey, according to the statement.

This finding is rare in wild mammals but is not surprising as EEE-positive mosquitoes have been documented by the Connecticut Agricultural Experiment Station in nearby towns.

This finding also indicates that the EEE virus is present in mammal-biting mosquitoes, which has prompted Connecticut’s Mosquito Management Program to advise residents to take precautions to protect themselves from mosquito bites. These measures include wearing mosquito repellent and covering bare skin, especially during dusk and dawn when mosquitoes are most active.

“DEEP urges residents to continue to take appropriate precautions to avoid contact with mosquitoes,” DEEP Commissioner Katie Dykes said in a statement. “With EEE now detected in mammal-biting mosquitoes in Eastern Connecticut, residents should continue to be vigilant when taking part in outdoor activities to avoid exposure to mosquito bites.”

DEEP made the following recommendations for residents to avoid mosquito bites:

• Minimize time outdoors when mosquitoes are most active, especially dawn and dusk
• Consider using mosquito repellents containing an EPA-approved active ingredient, including DEET, Picaridin, IR3535, oil of lemon eucalyptus, para-methane-diol (PMD), or 2-undecanone
• After returning indoors, wash any treated skin with soap and water
• Wear shoes, socks, long pants, and a long-sleeved shirt when outdoors for long periods of time, or when mosquitoes are more active
• Use mosquito netting when sleeping outdoors or in an unscreened structure and to protect infants when outdoors

More information is available at the Connecticut Mosquito Management Program website.