The state has now trapped 21 mosquitoes this season that have tested positive for West Nile Virus.
The number is a large jump from the last report from the Connecticut Agricultural Experiment Station, which last week said only two mosquitoes had tested positive for the virus.
The mosquitoes that tested positive for West Nile Virus in the past week were trapped in Bridgeport, Darien, Greenwich, and Stamford.
The state has tested more than 126,000 mosquitoes so far this season.
None has tested positive for Eastern Equine Encephalitis.