Two invasive tick species establish populations in three Connecticut coastal counties

Two invasive tick species, the lone star tick and the Asian longhorned tick, have established populations in Fairfield, New Haven, and New London counties in Connecticut. These non-native species feed on white-tail deer and can transmit Ehrlichiosis, a dangerous bacterial illness. Additionally, lone star ticks spread alpha-gal syndrome, a life-threatening red meat allergy. Experts warn coastal residents to remain on high alert due to heavy infestations.

Invasive tick species spread

• ▪Two invasive tick species, the lone star tick and the Asian longhorned tick, have established populations in New Haven, Fairfield, and New London counties in Connecticut
• ▪The lone star tick and Asian longhorned tick populations in New London County, Connecticut are specifically located in the town of Waterford as of June 22, 2026

Lone star tick populations

• ▪Lone star ticks are an invasive species not native to Connecticut that feed on white-tail deer
• ▪Lone star ticks can transmit both Ehrlichiosis and alpha-gal syndrome to humans

Asian longhorned tick populations

• ▪Asian longhorned ticks can transmit Ehrlichiosis and potentially exchange disease agents with lone star ticks

Ehrlichiosis bacterial illness

• ▪Ehrlichiosis can be dangerous to human health if the bacterial illness is left untreated
• ▪Ehrlichiosis is a tick-borne bacterial illness that causes flu-like symptoms including fever, headache, muscle aches, and fatigue

Alpha-gal syndrome risk

• ▪Alpha-gal syndrome is a potentially life-threatening allergy to a molecule found in beef, pork, and dairy that can develop after a tick bite
• ▪Individuals with alpha-gal syndrome can experience allergic reactions after eating red meat or being exposed to products containing alpha-gal

Public health alerts

• ▪The Connecticut Department of Public Health provides tick removal resources to assist residents
• ▪Health experts advise residents of Fairfield and New Haven counties, particularly in coastal communities, to be on high alert for heavy tick infestations