The Bugs Of Summer: CT Begins Monitoring For Mosquito-Borne Diseases

CONNECTICUT — The state has begun monitoring mosquitoes for the presence of viruses that can cause illness in people, including West Nile virus and eastern equine encephalitis virus.

The Connecticut Agricultural Experiment Station announced its mosquito trapping and testing program began Tuesday and will run through October.

"Each summer, we trap and test mosquitoes in locations throughout Connecticut to monitor the risk of mosquito-borne diseases throughout the state." said Philip Armstrong, medical entomologist at CAES. "Typically, West Nile virus activity peaks from July-September and occurs primarily in urban and suburban communities in the state. EEE virus transmission, in contrast, is more unpredictable from year to year and occurs later in the season, primarily in rural communities in southeastern Connecticut."

Last season, WNV was detected in 185 mosquito pools from 24 towns in six counties in Connecticut. The majority of WNV activity was detected in densely populated urban and suburban regions in Fairfield, Hartford, and New Haven counties. Seven human cases of WNV-associated illness were reported, with dates of onset from Aug. 11 to Sept. 20. WNV occurs every summer in the Northeast and has become the main cause of mosquito-borne illness in this region since it was first introduced into the New York City area in 1999.

EEE virus was not detected in the state during 2022. EEE is a rare but serious illness in humans with 4-8 cases reported in a typical year in the U.S. The last major outbreak occurred in 2019 when the number of confirmed human cases rose to 38 with 4 cases and three fatalities occurring in Connecticut.

“While we should all be outside enjoying the great weather, I want to encourage everyone to follow some best practices to prevent mosquito bites,” said Connecticut Department of Public Health Commissioner Dr. Manisha Juthani. “You can become very ill from WNV or other mosquito-borne illnesses. This goes for any age although anyone over the age of 60 is at a greater risk. Taking some simple steps can make a vital difference.”

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

• Minimize time spent outdoors between dusk and dawn, when mosquitoes are most active.
• Be sure door and window screens are tight-fitting and in good repair.
• 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 made of tightly woven materials that keep mosquitoes away from the skin.
• Use mosquito netting when sleeping outdoors or in an unscreened structure and to protect small babies when outdoors.
• Consider the use of an EPA-registered mosquito repellent, according to directions, when it is necessary to be outdoors.