Lyme Disease

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CDC Lyme Disease Data & Surveillance       

Lyme Disease is a tick-born bacterial infection that can be transmitted to humans and pets by infected ticks. Chester County is rural and suburban, making it a prime habitat for deer ticks which can carry the Lyme disease bacteria.

View the 2022 Lyme Disease Report to learn about the prevalence of Lyme Disease in the Chester County area.


3-30 Days post-tick bite

  • Red, expanding rash called erythema migrans (EM)
  • Fatigue, chills, fever, headache, muscle and joint aches, and swollen lymph nodes

Some people may get all of these symptoms, some may get the general symptoms without the rash.

Some people get a small bump or redness at the site of a tick bite that goes away in a few days. This is not a sign that you have Lyme disease. However, ticks can spread other organisms that may cause a different type of rash.

Lyme Map

Days/Weeks after bite

Untreated, the infection may spread from the site of the bite to other parts of the body, producing specific symptoms that may come and go, including:
  • Additional EM lesions in other areas of the body
  • Facial or Bell's palsy (loss of muscle tone on one or both sides of the face)
  • Severe headaches and neck stiffness due to meningitis
  • Pain and swelling in the large joints such as knees
  • Shooting pains that may interfere with sleep
  • Heart palpitations and dizziness due to changes in heartbeat (Lyme Carditis)
Many of these symptoms will resolve over a period of weeks to months, even without treatment. However, lack of treatment can result in additional complications.

Months/years after bite

Approximately 60% of patients who go untreated may begin to have bouts of arthritis, with severe joint pain and swelling. Large joints are most often affected, particularly the knees. Up to 5% of untreated patients may develop chronic neurological complaints months to years after infection. These include shooting pains, numbness or tingling in the hands or feet, and problems with short-term memory.

Lingering symptoms after treatment

Approximately 10-20% of patients with Lyme disease have symptoms that last months to years after treatment with antibiotics. These symptoms can include muscle and joint pains, cognitive defects, sleep disturbance, or fatigue. The cause of these symptoms is not known, but there is no evidence that these symptoms are due to ongoing infection from Lyme disease.This condition is referred to as Post-treatment Lyme disease syndrome (PTLDS). There is some evidence that PTLDS is caused by an autoimmune response, in which a person's immune system continues to respond, doing damage to the body's tissues, even after the infection has been cleared. Studies have shown that continuing antibiotic therapy is not helpful and can be harmful for persons with PTLDS.


Precautions should be taken in high risk area such as damp, grassy, or wooded regions or when outside for an extended period of time while doing yard work, gardening, hiking, etc.
  • Wear clothing that covers the skin and tuck loose pants into socks.
  • Wear light colored clothing because ticks are easier to spot and brush off.
  • Apply an insect repellent with 20-30% DEET to exposed skin other than the face and/or apply permethrin to clothes. Be sure to follow the manufacturer's instruction.
  • Walk in the center of trails to avoid contact with overgrown grass and brush.
  • Use a high-heat dryer for one hour after washing clothes. This will kill most ticks that might have been attached to clothing.
  • Keep grass mowed and trees trimmed.
  • Remove brush or leaf piles accumulated around stone walls or wood piles.
  • Create a woodchip or mulch barrier between woodlands and your yard. Place swing sets and other play equipment in mulched areas away from surrounding woodland edges.
  • Most importantly, check yourself, your family, and your pets frequently for ticks.
    • Bathe or shower as soon as possible after coming indoors to wash off and find ticks more easily that may be crawling on you.
    • Conduct a full-body tick check in front of a mirror to view all parts of your body when returning from potentially tick-infested areas.
    • Parents should take extra care and check their children for ticks.
  • Create a Tick-Safe Zone Through Landscaping

Tick Removal

Remove a tick from your skin as soon as you notice it. Use fine-tipped tweezers to firmly grasp the tick very close to your skin. With a steady motion, pull the tick's body away from your skin. Then clean your skin with soap and warm water. 

Avoid crushing the tick's body. Do not be alarmed if the tick's mouth parts remain in the skin. Once the mouth parts are removed from the rest of the tick, it can no longer transmit the Lyme disease bacteria. If you accidentally crush the tick, clean your skin with soap and warm water or alcohol.

Don't use petroleum jelly, a hot match, nail polish, or other products to remove a tick.

Preserve the tick if possible in case symptoms start to occur. The blacklegged tick, or deer tick, is the only tick known to carry and transmit Lyme disease to humans. 

Request a Lyme Disease Presentation

The Health Department offers educational programs for adults and children on how Lyme disease is transmitted and ways to prevent tick bites. The program also identifies different types of ticks and proper tick removal. Educational brochures and tick identification cards are available at the Health Department's Resource Center. For more information or to schedule a presentation, call 610-344-6225.