Press Releases

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Risk of West Nile Virus Continues

Positive Mosquitoes Detected in 23 Connecticut Towns

Dr. Philip Armstrong
The Connecticut Agricultural Experiment Station
123 Huntington St.
New Haven, CT 06511
Phone: 203-974-8510; Email:

Dr. Jason White
The Connecticut Agricultural Experiment Station
123 Huntington St.
New Haven, CT 06511
Phone: 203-974-8440; Email:

New Haven, CT – The State Mosquito Management Program is warning Connecticut residents about the increased risk of infection by West Nile virus (WNV) this season. So far, the Connecticut Agricultural Experiment Station (CAES) has detected WNV-infected mosquitoes in: Branford, Bridgeport, Cornwall, Darien, Fairfield, Greenwich, Hartford, Ledyard, Meriden, Milford, New Canaan, New Haven, Newington, Norwalk, Stamford, Stratford, Wallingford, Waterbury, Waterford, West Haven, Westport, Wilton, and Woodstock. There are no human cases of WNV so far this season.

“We continue to see high numbers of mosquitoes carrying West Nile virus, especially in coastal Fairfield and New Haven counties and in the greater Hartford area,” said Dr. Philip Armstrong, Medical Entomologist at the CAES. “This includes mosquito species that feed readily on humans, which increases the risk of infection. Now is the critical time of year when virus activity reaches its peak in the mosquito population."

“August and September are the months when people are at greatest risk of West Nile virus infection,” said Dr. Jason White, Director of CAES. “We strongly encourage Connecticut residents to take simple steps to prevent mosquito bites, such as using insect repellent and covering bare skin, especially during dusk and dawn when biting mosquitoes are most active.”

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.

Figure 1. Connecticut towns in which WNV-infected mosquitoes have been detected in 2022.

Map showing the Connecticut towns in which West Nile virus-infected mosquitoes have been detected in 2022.

Figure 2. Weekly number of WNV-positive mosquito pools detected in 2022 compared to the 16 year average.

Graph showing the weekly number of West Nile virus-positive mosquito pools detected in 2022 compared to the 16 year average.

Connecticut Mosquito Management Program

The response to mosquito transmitted diseases in Connecticut is a collaborative inter-agency effort involving the Department of Energy and Environmental Protection (DEEP), The Connecticut Agricultural Experiment Station (CAES), the Department of Public Health (DPH), the Department of Agriculture, and the Department of Pathobiology at the University of Connecticut (UCONN). These agencies are responsible for monitoring mosquito populations and the potential public health threat of mosquito-borne diseases.

The CAES maintains a network of 108 mosquito-trapping stations in 88 municipalities throughout the state. CAES begins mosquito trapping and testing in June and continues into October. Positive findings are reported to local health departments and on the CAES website.

For information on WNV and other mosquito-borne diseases, what can be done to prevent getting bitten by mosquitoes, the latest mosquito test results, and human infections, visit the Connecticut Mosquito Management Program website.