The state Department of Public Health today is urging residents to minimize outdoor activity from dusk to dawn, when mosquitoes are most active, because of eastern equine encephalitis.
The state is issuing the warning in the hopes that residents will take preventive measures to avoid mosquito bites and reduce the chances of contracting eastern equine encephalitis, of EEE.
State officials said the mosquitoes that carry the virus are active until the first heavy frost.
The EEE virus has been identified in mosquitoes in 12 towns and in horses in two other towns.
Towns where mosquitoes have tested positive for EEE include Chester, Haddam, Hampton, Groton, Killingworth, Ledyard, Madison, North Stonington, Plainfield, Shelton, Stonington, and Voluntown.
Horses have tested positive for EEE virus in Colchester and Columbia this season, and the virus has been detected in a flock of wild pheasants, according to the Department of Public Health.
No human cases of EEE have been identified in Connecticut so far this year.