First CT Mosquitoes This Year Test Positive For EEE Virus: Now What?

CONNECTICUT — Mosquitoes in Connecticut have tested positive for the Eastern Equine Encephalitis virus for the first time this season.

EEE is the most severe mosquito-transmitted disease in the U.S. with approximately 40 percent mortality and significant brain damage in most survivors.

The bugs were trapped in Thompson on August 24, according to the Connecticut Agricultural Experiment Station. The mosquitoes were Culiseta melanura, a predominately bird-biting species.

“The recent detection of EEE virus and continued spread of West Nile virus is cause for concern as conditions are suitable for further build-up of virus in the coming weeks” said Philip Armstrong, medical entomologist at CAES.

Earlier this week, state scientists determined that West Nile virus had found its way into 25 Connecticut towns.

EEE is a more rare (4-8 cases reported per year in the U.S.), and much more serious disease than WNV. The latter has gotten more press because its virus-bearing mosquitoes go where the people are, in the more densely populated urban and suburban parts of the state.

The last major outbreak of EEE occurred in 2019, involving 38 human cases nationally with 19 cases occurring in New England. The virus was detected in 28 communities in Connecticut, with a total of 122 positive mosquito samples. There were four confirmed human cases of EEE and three people died. Most virus activity occurred in Middlesex, New London, and Windham Counties, consistent with prior years. EEE is typically found in the freshwater swamps and more rural areas.

"We will continue to closely monitor mosquitoes for virus amplification, and we encourage everyone to take simple measures such as wearing mosquito repellent and covering bare skin, especially during dusk and dawn when mosquitoes are most active," Armstrong said.

To reduce the risk of being bitten by mosquitoes, residents should:

• Minimize time spent outdoors between dusk and dawn when mosquitoes are most active.
• Consider the use of mosquito repellents containing an EPA-registered active ingredient, including DEET, Picaridin, IR3535, oil of lemon eucalyptus, para-methane-diol (PMD), or 2-undecanone when it is necessary to be outdoors.
• Wear shoes, socks, long pants, and a long-sleeved shirt when outdoors for long periods of time, or when mosquitoes are more active. Clothing should be light-colored and loose-fitting and made of tightly woven materials that keep mosquitoes away from the skin.
• Be sure door and window screens are tight-fitting and in good repair.
• Use mosquito netting when sleeping outdoors or in an unscreened structure and to protect infants when outdoors.