Press Releases
06/01/2022
State Mosquito Monitoring Program Begins Testing for Mosquito-Borne Viral Diseases
New Haven, CT - The State of Connecticut Mosquito Management Program today announced it is monitoring mosquitoes for the presence of viruses that can cause illness in people including West Nile virus (WNV) and eastern equine encephalitis (EEE) virus. The mosquito trapping and testing program, coordinated by The Connecticut Agricultural Experiment Station (CAES), will begin May 31 until the end of October.
"We will be trapping and testing mosquitoes from 108 locations statewide from now until October," said Dr. Philip Armstrong, Medical Entomologist at CAES. "Typically, West Nile virus activity peaks from July-September, especially in densely-populated areas of lower Fairfield and New Haven Counties, and the Hartford metropolitan area. Seasonal transmission of EEE virus, in contrast, occurs more sporadically with focal areas located in rural areas of eastern Connecticut."
Last season, WNV was detected in 208 mosquito pools from 43 towns in all eight counties in Connecticut. Six confirmed human cases of WNV infection were reported from Fairfield, Hartford, and New Haven Counties with dates of onset from August 20 to October 10. 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.
During 2021, EEE virus was detected in two mosquito pools collected from one town in New London County. There were no EEE infections reported in humans or horses. EEE is a rare but serious illness in humans with 4-8 cases reported in a typical year in the U.S. During 2019, the number of confirmed human cases rose to 38 with 4 cases (3 fatalities) occurring in Connecticut.
To reduce the risk of being bitten by mosquitoes, 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.
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. Mosquito traps are set Monday – Thursday nights at each site every 10 days on a rotating basis and then twice a week after detection of virus. Mosquitoes are grouped (pooled) for testing according to species, collection site, and date. Positive findings are reported to local health departments and on the CAES website.
For information on WNV and EEE, 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.