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State guide · PennsylvaniaLyme disease in Pennsylvania
Pennsylvania reports more Lyme disease than almost any other state. Here are the latest numbers, where the risk is, how to protect yourself, and where to turn for care.
Case numbers are from CDC’s 2023 annual notifiable disease tables. The rate uses U.S. Census 2023 population estimates. Real infections are higher than reported cases.
How high is the risk in Pennsylvania?
High, and it’s statewide. In 2023, Pennsylvania reported 16,671 cases of Lyme disease, second only to New York. With about 13 million residents, that works out to roughly 129 cases for every 100,000 people, one of the highest rates in the country.
Blacklegged ticks, the ticks that spread Lyme, were once rare in the state. In 2015, researchers reported finding them, along with the Lyme bacterium, in all 67 Pennsylvania counties. Historically, the eastern and central parts of the state have reported more cases than the west, but no part of Pennsylvania is free of risk.
How Pennsylvania compares with its neighbors (2023)
| State | Reported cases | Per 100,000 |
|---|---|---|
| West Virginia | 3,242 | 183 |
| Pennsylvania | 16,671 | 129 |
| New York | 22,173 | 113 |
| New Jersey | 7,224 | 78 |
| Maryland | 2,470 | 40 |
| Delaware | 349 | 34 |
| Ohio | 1,307 | 11 |
When ticks are most active in Pennsylvania
The highest-risk months for Lyme are late spring and summer, when young ticks called nymphs are out. Nymphs are about the size of a poppy seed and easy to miss. Adult blacklegged ticks are active in the fall and can bite on warm days through winter, so tick checks matter well beyond summer.
Ticks wait in tall grass, brush, leaf litter and the edges of wooded areas, including backyards. Gardening, hiking, hunting and walking the dog all count as exposure.
How to protect yourself
- Use an EPA-registered insect repellent, such as one with DEET, picaridin, IR3535, oil of lemon eucalyptus, PMD or 2-undecanone.
- Treat clothing and gear with permethrin, or buy pre-treated clothing.
- Check your whole body for ticks after time outdoors, including your scalp, armpits, groin and behind your knees, and check children and pets too.
- Shower soon after coming indoors.
- Tumble dry clothes on high heat for 10 minutes to kill ticks on dry clothing.
Found a tick attached? Remove it right away with fine-tipped tweezers. Here’s CDC’s step-by-step method and what to watch for afterward.
Other tick-borne illnesses in Pennsylvania
Blacklegged ticks can carry more than Lyme. Pennsylvania also sees cases of anaplasmosis and babesiosis, and occasionally Powassan virus, which is rare but can be serious. If you get sick after a tick bite and you’re not improving, ask your provider whether another tick-borne infection could be involved.
Where to get care in Pennsylvania
Start with your primary care provider or an urgent care clinic, especially if you have a rash or fever after a tick bite. Lyme is common enough in Pennsylvania that most clinicians see it regularly. For complicated or lingering symptoms, ask about a referral to an infectious disease specialist, or to a rheumatologist for joint problems or a neurologist for nerve symptoms.
We’re building a list of Pennsylvania clinics and providers who treat tick-borne illness, drawn from public information and listed without endorsement. Are you a Pennsylvania clinic? Contact us.
State resources
- Pennsylvania Department of Health: tick-borne diseases, which tracks tick-borne diseases and issues health advisories
- Pennsylvania Department of Environmental Protection, which runs the state’s tick surveillance program
We are collecting real experiences about Lyme in Pennsylvania from people who have lived it, shared with their permission. As stories come in, they will appear here, clearly marked as personal experience rather than medical advice.
Frequently asked questions
Is Lyme disease common in Pennsylvania?
Yes. Pennsylvania reported 16,671 cases in 2023, the second-highest number of any state, and blacklegged ticks have been found in all 67 counties.
What part of Pennsylvania has the most Lyme disease?
Historically the eastern and central regions report the most cases, while the west has reported fewer. Risk exists statewide, so take precautions wherever you live or travel in Pennsylvania.
What tick carries Lyme disease in Pennsylvania?
The blacklegged tick, often called the deer tick. The American dog tick and the lone star tick, which also live in Pennsylvania, do not spread Lyme.
Can you get Lyme disease in winter in Pennsylvania?
It’s less likely, but adult blacklegged ticks can be active on warm winter days, so keep checking for ticks after time outdoors.