June 24, 2022: The Centers for Disease Control and Prevention has listed Fairfield, Hartford, New London, Middlesex, Tolland, and Windham Counties in Low/Green the as part of its COVID-19 Community Levels Map. Only Litchfield, Middlesex and New Haven County are listed in the Medium/Yellow category. Residents who live in the Medium /Yellow counties who are at a high risk for severe illness, should talk to their health care provider about whether to wear a mask and take other precautions. These residents should stay up to date with their COVID-19 vaccines and get tested if they have symptoms. Visit the CDC COVID-19 Community Levels Map for updates.

West Nile Virus Statistics


West Nile virus (WNV) was first identified in Connecticut in 1999. To help learn more about the epidemiology of WNV in Connecticut, the Department of Public Health (DPH) in collaboration with other state agencies and local governments implemented surveillance systems in 2000. These surveillance systems included tracking WNV infections in humans, horses, wild birds, and mosquitoes.  During the first 5 years, it was determined that mosquito surveillance was the best sustainable indicator of potential human infections, therefore wild bird monitoring was discontinued in 2006. The DPH continues to monitor WNV in humans, horses, and mosquitoes.


The Connecticut Agricultural Experiment Station maintains 91 mosquito trap sites in 73 towns statewide. The trapping sites were selected based on habitat, proximity to residential areas, and historical findings. Results provide information on the numbers and types of mosquitoes present, as well as the rates of infection with WNV and other viruses that may have public health importance. The information obtained through surveillance helps guide statewide prevention and control measures.



   (Additional information and mosquito testing results.)


To contact the Epidemiology and Emerging Infections Program, please call 860-509-7994.