For the first time, blacklegged (deer) ticks have now been observed in all 67 counties of Pennsylvania, according to researchers at The Department of Environmental Protection (DEP). The range expansion took place in just decades, as similar studies conducted in the mid-1960s found no specimens.

Black-legged tick
Ixodes scapularis, a Black-legged tick/CDC

DEP’s Vector Management Program, in collaboration with the Indiana University of Pennsylvania, published the findings on the risk of tick-borne disease in Pennsylvania in the Journal of Medical Entomology on April 14. The study was authored by the DEP Vector Management team of Mike Hutchinson, Maria Strohecker, Andy Kyle, and Matt Helwig and Indiana University of Pennsylvania Professor of Biology Dr. Tom Simmons.

The research found Ixodes scapularis, the blacklegged tick, and Borrelia burgdorferi, the causative agent of Lyme disease, present in all 67 counties of Pennsylvania. The research also found that in recent years the blacklegged tick has become imbedded in western Pennsylvania, though the prevalence rate of Lyme disease still remains relatively lower than the rest of the state. The blacklegged tick is the primary carrier of Lyme disease, an infectious disease caused by the bite of an infected tick that can cause fever, fatigue, headache, muscle aches, and joint pain.

“DEP’s Vector Management team’s confirmation of the high risk of Lyme disease in every county of the Commonwealth verifies that every Pennsylvanian, from Philadelphia to Erie, must take precautions to prevent the spread of Lyme disease,” said acting DEP Secretary John Quigley.

“The first line of defense against Lyme disease and any other tick-borne illnesses is avoiding tick infested areas. We know, however, that as the weather becomes nicer many residents spend more time outdoors. We suggest that people wear protective clothing, use insect repellent (i.e. DEET), and do a full body check after spending time outdoors,” said acting Physician General Dr. Rachel Levine.

The study also confirmed the presence of two other human pathogen diseases, Babesiosis and Anaplasmosis, in Pennsylvania blacklegged ticks. The prevalence rates of these two diseases were much lower than Lyme disease.

Pennsylvania has reported the most cases of Lyme disease in the nation for the past five years. All Pennsylvanians are encouraged to take precautions to prevent the spread of tick-borne illnesses.

“Parents should check their children for ticks. Showering within two hours of outdoor exposure may also help prevent transmission. If an individual has been bitten by a tick, we recommend that they remove the tick carefully with a set of fine tipped tweezers. If an individual develops signs and symptoms of Lyme disease after a tick bite, we urge them to seek medical attention. Early diagnosis and treatment of Lyme disease may prevent late-stage complications,” Dr. Levine said.