Scientists Report First Human Case Of Emerging Tick Disease In CT

CONNECTICUT — State entomologists are reporting that an emerging tick-borne illness, similar to Rocky Mountain spotted fever, has been diagnosed in a Connecticut resident.

Transmitted by the Gulf Coast tick, R. parkeri rickettsiosis is relatively milder than RMSF, but this is the first report of this disease in the Northeast, Connecticut Agricultural Experiment Station scientists said Monday.

The disease joins an already overflowing roster of tick-borne ailments prevalent in the Northeast, including Lyme disease, babesiosis, anaplasmosis, Powassan virus disease, and ehrlichiosis.

The report was published in the "Emerging Infectious Diseases Journal," and is based on collaborative field and laboratory investigations by the CAES and CDC scientists on the tick that transmitted the disease and clinical investigations of the affected patient.

The distribution of the tick was considered restricted predominantly to coastal regions of states bordering the Gulf of Mexico and the southern Atlantic coast, according to Dr. Goudarz Molaei, a research scientist and medical entomologist with CAES. But in recent decades, its range has expanded northward into the mid-Atlantic states, with new populations reported from Delaware and Maryland.

According to Molaei, the first established population of the Gulf Coast tick was reported in Fairfield County in 2021, with a 30 percent infection with R. parkeri. Additional populations of this tick species with higher infections were later reported from New York and New Jersey in 2022 and 2024, respectively. Scientists believe that migratory grassland birds serve a crucial role in the spread of Gulf Coast ticks to locations in central and northern states that possess favorable environmental conditions for their survival.

"Because of morphological similarities between Gulf Coast ticks and American dog ticks (the principal vector of RMSF in the Northeast), these two species can be misidentified. Since most tick species are associated with a unique suite of pathogens, it is important to improve regional capacity for accurate detection and identification of ticks and the pathogens these transmit in the Northeast, an area already endemic for Lyme disease, RMSF, ehrlichiosis, anaplasmosis, babesiosis, and Powassan virus disease," Molaei said.

For more information about ticks in Connecticut, visit the CAES website here.