The height of tick season is underway, and Pennsylvanians are encouraged to be cautious since the commonwealth has the most cases of the tick-spread Lyme disease in the United States.

Historical data shows the peak season of tick exposure is Memorial Day weekend through July - and this year is no exception.

“Current trends show this year’s tick activity to be higher than last year,” Dr. Nicole Chinnici, director of Pennsylvania Tick Research Lab at East Stroudsburg University, said.

The lab tracks results of ticks submitted for testing, and the U.S. Centers for Disease Control and Prevention also keeps tallies of cases of Lyme and other tick-spread diseases.

The most recent CDC data notes Pennsylvania has 29.2% of the country’s cases, followed by the neighboring states of New Jersey at 11.7% and New York at 11.6%.

The CDC further reports seven of the top 10 most affected counties in the nation with Lyme disease are in the western and southeastern parts of Pennsylvania.

Lyme disease is caused by a bacteria spread by the bites of blacklegged ticks, also called deer ticks. Left untreated, it can produce a wide range of symptoms, depending on the stage of infection. These include fever, rash, facial paralysis, an irregular heartbeat and arthritis, the CDC notes.

According to surveillance studies conducted by the Pennsylvania Department of Environmental Protection, nymphal ticks, which are out in Pennsylvania from late May to late July, have a 1 in 4 chance of being infected the Lyme-causing bacteria. Adult ticks, which are out from late September to May of the following year, have a 1 in 2 chance of being infected.

The Pennsylvania Department of Health noted 8,413 Lyme disease cases were reported in Pennsylvania in 2022 or about 64.9 cases per 100,000 people. But the department said the number of actual cases is likely much higher - up to 10 times higher.

Residents can keep a check on where ticks are prevalent through the department’s recently launched online tickborne diseases dashboard.

“Pennsylvania has incredible outdoor recreational opportunities, and we want to provide as much information as possible for residents to enjoy them safely,” Acting Secretary of Health Dr. Debra Bogen said.

The dashboard tallies the year’s Lyme disease cases by county. To date, Lehigh County has had 21 cases; Northampton, 19; Carbon, 5; Schuylkill, 7; and Monroe, 12.

Lyme isn’t the only disease to worry about. Ticks can cause a host of other infections including anaplasmosis, babesiosis, powassan virus and Rocky Mountain spotted fever.

Pennsylvania Tick Research Lab has been providing free tick testing to Pennsylvania residents since 2018. The lab tests ticks and keeps track of the results, including types of ticks, diseases carried and the geographic region it was submitted from.

Chinnici noted 54% of tick exposures were reported from backyards when residents were playing or doing yard work.

“At home is where we most often let our guard down,” she said.

The tick lab has tested more than 76,000 ticks since it started the program in June 2019. More than 54,000 of them, or about 71%, were not infected.

The lab encourages tick submissions, and those who are exposed are advised to remove it with a fine point tweezer and place it in a plastic zip-top bag. Residents can mail it to the lab after following instructions on ticklab.org/test-my-tick. Tests are free thanks to a grant from the health department.

Due to a recent fire, however, tests may be delayed as lab equipment is moved.

Those who find attached ticks should remove them immediately.

“The tick must be attached for at least 24 hours to begin transmitting Lyme disease and in most cases, it must be attached for 36 to 48 hours,” the health department notes. “If a patient can be sure the tick was only attached for a short period of time, there is no risk of Lyme disease. However, other tickborne diseases may require shorter attachment times.”

Preventing exposure to ticks is key. It is recommended those who will be spending time outdoors wear light-colored clothing to easily spot crawling ticks and tuck pants into socks and shirts into pants to avoid ticks crawling under clothing and attaching. Thorough tick checks should be undertaken, and a shower is recommended within two hours of being outside.

The health department also recommends:

• Walking in the center of trails and avoiding areas with high grass and leaf litter

• Using EPA-approved insect repellents on exposed skin

• Using products that contain 0.5% permethrin to pretreat shoes, clothing and gear

• Placing clothing worn outdoors in the dryer on high heat for 10 minutes to kill ticks