Emergency room visits tied to tick bites are hitting springtime highs, with Pennsylvania—especially the Pittsburgh region—recording a disproportionate share. The CDC says tick activity has accelerated with warmer temperatures, while local health data underscor
For many people, a tick bite is easy to dismiss—until a trip to the emergency room forces it into focus.
This spring. ER visits related to tick bites have climbed to their highest spring levels since 2017. and Pennsylvania accounts for a massive percentage of those cases. The Centers for Disease Control and Prevention linked the seasonal uptick to increased tick activity across the Northeast and Midwest as warmer temperatures change when and where ticks thrive.
Pennsylvania already has one of the worst records in the country for Lyme disease. the most common tick-borne illness in the U.S. An estimated 476,000 people receive treatment for Lyme disease each year nationwide. In 2024 alone, Pennsylvania reported 8,413 confirmed cases of Lyme disease, with an incidence rate of 6.47.
Pennsylvania’s heavy burden shows up in rankings built from federal data. One analysis ranked Pennsylvania as the worst state for Lyme disease. reporting that the state accounted for 29.2% of all reported cases between 2016 and 2019. using CDC data. Another ranking placed Pennsylvania at No. 9 in 2024.
Tick activity rising with the seasons has also raised public health pressure. The CDC warning comes as people move through yards, parks, and wooded areas—places where ticks can wait for a host in leaf litter, tall grass, and logs.
In the Pittsburgh region, Lyme disease remains the lead concern. Allegheny County reported 1,485 cases of Lyme disease in 2023, the last year data was available, according to the CDC. Lyme disease is caused by bacteria called Borrelia burgdorferi, carried by infected ticks. Tick bites—especially those from blacklegged ticks—are the most common route for the bacteria to spread to humans. Because the blacklegged tick is small and its bite can go unnoticed. not everyone who develops Lyme disease symptoms remembers being bitten by a tick. according to Harvard Health.
Lyme disease doesn’t spread from every tick, and the variation can be stark. Johns Hopkins Medicine says that fewer than 1% of ticks in some regions carry the bacteria that cause Lyme disease. while in other areas. as many as half of ticks are infected. In Pennsylvania. tick species found locally include blacklegged ticks. American dog ticks. lone star ticks. and groundhog ticks. according to Pennsylvania State University.
Only two tick species can spread Lyme disease. One of those species lives in Pittsburgh. The blacklegged tick and the Western blacklegged tick, also known as deer ticks, can transmit the illness, which most often shows up in the Upper Midwest, Northeast, and Mid-Atlantic states.
Symptoms often arrive after a delay. Within three to 30 days after a bite from an infected tick. the CDC lists fever. chills. headache. fatigue. muscle aches and joint pain. swollen lymph nodes. and erythema migrans rash—which may appear like a “bull’s-eye.” If Lyme disease is left untreated. the CDC warns symptoms can progress to severe headaches and neck stiffness. additional rashes. facial palsy. arthritis. intermittent pain in tendons. muscles. joints and bones. heart palpitations or an irregular heartbeat. dizziness or shortness of breath. inflammation of the brain and spinal cord. nerve pain. and shooting pains. numbness. or tingling in the hands and feet.
Pittsburgh’s risk doesn’t stop at Lyme. Anaplasmosis is another illness transmitted by the blacklegged tick, according to the Allegheny County Health Department. Cases have increased over the past few years. The illness. caused by the bacterium Anaplasma phagocytophilum. may cause fever. chills. headache. body aches. fatigue. nausea. vomiting and abdominal pain. and it can lead to bleeding problems. respiratory failure. and organ failure if left untreated.
Other tick-borne illnesses found in Pennsylvania include hard tick relapsing fever, ehrlichiosis, spotted fever rickettsioses, babesiosis, Powassan virus, Alpha gal syndrome, and Heartland virus.
The timing matters. Tick season in Pittsburgh peaks in June. when immature ticks—hatched the previous year—emerge from leaf litter where they spent the winter dormant. according to the Pennsylvania Department of Health. The risk for picking up ticks is highest in wooded areas or parts of the city with overgrown grass. because ticks prefer shady. damp environments such as leaf litter. tall grass. and logs. Tick levels stay highest through July, ebbs in August, and plummets in September, according to the state department of health. Risk jumps again in October and November before dropping off for the winter. with active ticks persisting in wooded areas in autumn.
What happens next often comes down to how quickly someone checks and removes ticks. The CDC says that for Lyme disease to be transmitted. a tick is usually connected to its host for 24 to 36 hours. Other tick-borne diseases can spread faster—sometimes in as little as 15 minutes. Removing the tick promptly can reduce the chance of becoming infected.
A preventative check starts immediately after time outdoors. The U.S. Forest Service recommends checking clothes by removing them and looking for hitchhiking ticks on shoes. backpacks. and outer layers of clothing. It also advises taking a shower or bath as soon as returning from high-risk areas to remove unattached ticks and help find any that have attached. A mirror check—using a full-length or handheld mirror—can help people spot tiny black dots that may resemble new freckles. The guidance also emphasizes hidden spots where ticks prefer warm. dark. and moist areas: hair. around the ears. underarms. groin. behind the knees. between the toes. and even the belly button.
While national ER visits for tick bites are rising. Pittsburgh’s season has its own rhythm—June peak. sustained risk through July. a drop in September. then another round of danger in October and November. In a state already carrying thousands of confirmed Lyme cases. the difference between noticing a tick early and missing it can be the difference between a manageable course and symptoms that widen and intensify.
Finch Walker is the Pittsburgh Connect Reporter for the USA TODAY Network. Contact Walker at FWalker@usatodayco.com. Instagram: @finchwalker_. X: @_finchwalker.
tick bites Lyme disease Pennsylvania Pittsburgh emergency room visits CDC blacklegged ticks anaplasmosis deer ticks Allegheny County