Exotic Tick Species Detected In Connecticut On Travelers Returning From Overseas

CONNECTICUT — Scientists at the Connecticut Agricultural Experiment Station have identified four exotic tick species in the state in recent years, all found on people returning from overseas travel.

The ticks, closely related to species native to the United States, were collected from travelers between 2019 and 2023. While officials say the small number detected poses no immediate public health risk, they caution that travelers should check for ticks before returning home, particularly after spending time outdoors abroad.

“People should also conduct thorough tick checks while traveling, particularly following outdoor activity in potentially tick-infested areas, and be proactive in monitoring possible symptoms following a tick bite,” said Dr. Goudarz Molaei, research scientist and director of the CAES Passive Tick and Tick-Borne Disease Surveillance Program. He urged anyone who finds an attached tick to inform their physician and public health officials about recent travel to help identify the species and assess disease risk.

The species found include Amblyomma mixtum from Guatemala and Costa Rica, Amblyomma coelebs from Belize, Rhipicephalus pulchellus from Tanzania, and Ixodes ricinus from Germany, Poland and Scotland. Two A. mixtum ticks tested positive for Rickettsia amblyommatis, though its health impact remains unclear.

Researchers say globalization, increased travel, and the animal trade have accelerated the spread of invasive ticks, such as the longhorned tick, Haemaphysalis longicornis, now established in at least 24 states, including Connecticut.

The study, published in the journal iScience, is part of an ongoing effort to track invasive ticks and related pathogens. A full report is available online here.