The Connecticut Agricultural Experiment Station announced on March 23 the release of its sixth annual statewide active tick surveillance results, providing new data on tick populations and disease prevalence across Connecticut.
Researchers from the Center for Vector Biology and Zoonotic Diseases collected more than 10,000 ticks from 40 public locations in all eight counties during spring, summer, and fall of 2025. The ticks were tested for five pathogens that cause human diseases: anaplasmosis, babesiosis, Lyme disease, hard tick relapsing fever, and Powassan encephalitis.
Blacklegged ticks (Ixodes scapularis) remained abundant with 3,459 specimens identified. Longhorned ticks (Haemaphysalis longicornis), lone star ticks (Amblyomma americanum), and American dog ticks (Dermacentor variabilis) were also found. The report noted that higher numbers of longhorned and lone star ticks resulted mainly from isolated sampling events rather than widespread increases. New London County had the highest average adult blacklegged tick density at 81 per acre, while Litchfield County reported the highest nymphal density at 28 per acre. Testing showed Borrelia burgdorferi infection rates were highest in adult female ticks from Fairfield County (68%) and in nymphs from New Haven County (32%). Statewide infection rates in blacklegged ticks included Lyme disease at 55% for adults and 25% for nymphs; babesiosis at 14% for adults and 13% for nymphs; anaplasmosis at 9% for adults and 5% for nymphs; hard tick relapsing fever at 2% for both stages; and Powassan virus under one percent in adults.
“Ticks are still a common part of the Connecticut landscape, including both established and emerging species. People can come into contact with ticks in their own yards or while enjoying the outdoors, so taking preventative measures is key to lowering the risk of tick-borne illness,” according to Dr. Megan Linske.
Residents are encouraged to conduct routine tick checks after outdoor activities, wear protective clothing such as long sleeves and pants, tuck pant legs into socks when in tick-prone areas, and use permethrin-treated clothing to repel or kill ticks.
The Connecticut Agricultural Experiment Station was the first agricultural experiment station in the United States according to the official website. It maintains its main campus in New Haven as reported by the official website. The organization is governed by an eight-member Board of Control under statutory authority according to the official website. Its work focuses on research and education addressing agricultural, public health, and environmental challenges as said by the official website. The station receives support from its Research Foundation according to the official website.
More information about these findings is available on the official roster page.
