With ticks in their teeny-tiny nymph phase in Western Pa., now is the time to be extra vigilant with preventive measures
Mia Rose Kohn / Pittsburgh Post-Gazette
Pennsylvania’s warm spring and summer months breed more than lush landscapes: Young ticks are on the move in Allegheny County.
This season is looking to be particularly tick-heavy: Self reported tick bites, per the Pennsylvania Tick Research Lab, have already surpassed last year’s state-wide peak in July by 144%.
Carriers of Lyme disease and other illnesses, black legged ticks –– the most common species in Allegheny County –– put Pennsylvania in the lead for Lyme disease cases 11 out of the 12 years between 2011 and 2023, according to the U.S. Centers for Disease Control’s most recent data.
With most cases of the disease occurring in June, per experts, the Allegheny County Health Department (ACHD) has begun “ramping up efforts to protect the public,” collecting and testing tick populations on public lands as part of the 2025 Tick and Mosquito Surveillance Season, according a news release earlier this month. Pennsylvania residents can also consult the state Department of Health’s tick dashboard, which debuted in May 2024, track areas with the highest prevalence of the insects.
“The time to be concerned is now,” said Nick Baldauf, vector control coordinator at ACHD. In addition to Lyme, he said, cases of the newer tick-borne illness Anaplasmosis are increasing "exponentially."
Smaller ticks are harder to spot
Ticks will not immediately impact a human host, so spotting them early is key. They must be attached to skin for roughly 24-36 hours before they can infect a host, said Mr. Baldauf.
That makes June a particularly dangerous month for tick-borne illness, as the tick life cycle finds the insects in the smaller nymph stage –– and they’re more difficult to find on the body.
“The infection rates for the adult ticks are twice as high as the nymphs, but the adults are much larger,” said Mr. Baldlauf. “People can find those ticks before they get infected, so there's not a lot of disease transmission that occurs from the adult ticks.”
Roughly 20-30% of black legged nymphs carry Lyme disease, according to past data collected by Mr. Baldauf’s team.
Not all ticks carry diseases, but there are signs to look for if you have had contact.
“If you start feeling headaches, fever, joint pain, flu-like symptoms, there is a good chance that it could be some sort of tick-borne disease developing,” said Mr. Baldauf.
He stressed that the bull’s-eye-shaped rash commonly associated with tick bites doesn’t occur in all patients. Both he and his daughter had Lyme disease last year, for instance, and neither developed a rash.
According to the CDC, 70-80% of infected people develop a rash –– but it can take anywhere from three to 30 days to develop, and typically does not itch or burn.
To check if a tick is carrying Lyme or other diseases, Pennsylvania residents can mail the tick’s body to the Pennsylvania Tick Research Lab, based in East Stroudsburg, Pa., for free testing using a form on their website.
Blood tests for Lyme disease can also be ordered through a doctor, although an infected patient may not test positive for several weeks, warned Mr. Baldauf.
A newer disease on the rise
In 2011, the first case of another tick-borne illness, Anaplasmosis, was reported in Pennsylvania's western counties, according to a study by researchers at Penn State College of Medicine published in 2023 in the journal Open Forum Infectious Diseases. By 2019, cases climbed to just under 30; by 2021, 200 cases were reported in the state’s western counties, with 600 total recorded across the commonwealth.
Anaplasmosis is similar to Lyme disease, said Mr. Baldlauf. Symptoms including fever, chills, fatigue and muscle aches, and, as with Lyme, can be treated with antibiotics.
Symptoms typically begin within 1-2 weeks after a bite, according to the CDC, though Anaplasmosis, unlike Lyme, does not trigger a rash.
“We are seeing exponential increases in human cases,” said Mr. Baldauf.
ACHD recorded just under 90 cases of Anaplasmosis in 2023 –– roughly triple the nearly 30 cases reported in 2022.
Why cases are growing so rapidly, Mr. Baldauf said, is unclear. According to data collected by Mr. Baldauf’s team, roughly 10% of black legged nymphs in Allegheny County carried Anaplasmosis in the last several years.
Nicole Chinnici, director of the Pennsylvania Tick Research Lab, said the rate of infected ticks has remained steady statewide.
Tick bite prevention and treatment
If you find a tick on yourself, it’s important not to crush or scratch it, said Mr. Baldauf.
“The best way to remove a tick is to grab as closely as possible to the skin with fine-tip tweezers and pull straight up,” he said. “There's a lot of myths and misconceptions about other ways to remove ticks: burning matches, lit cigarettes, Vaseline. Those are all really bad ideas.”
These methods may cause a tick to bleed, releasing infected fluid. “You run the risk of injecting the pathogens into your own bloodstream,” said Mr. Baldauf.
The best protection, he said, is prevention, which includes:
• Performing frequent tick checks, looking behind ears, hair and any other warm, moist areas.
• Treating clothing and shoes with a chemical called permethrin, which is especially effective in repelling ticks in addition to other insects. “Treating your footwear with permethrin alone has been shown to make it 70 times less likely for you to get a tick-borne disease,” said Mr. Baldauf. ACHD also recommends using an insecticide with DEET or lemon eucalyptus oil.
• Avoiding brush and leaf litter on forest floors, especially when moist.
“They can be found in grass. They can be found in mulch beds. They can be in your gardens, right outside your house,” said Mr. Baldauf. “You don't have to be out hiking, you don't have to be camping. Most ticks are acquired through outdoor play, yard work and gardening.”
Why tick populations are rising
The annual number of tick-borne disease cases in the U.S. has more than tripled in the past two decades, according to the CDC. And Pennsylvania already has "perfect weather” for ticks, said Ms. Chinnici, with four distinct seasons and plenty for rain.
“We also have a variation of hosts for them,” she said. “We have a good landscape of forested area, plus suburban areas mixed in, and all of that contributes to having a really healthy tick population.”
There are not yet enough data from this season to say why the lab is recording higher tick populations than in past years –– something that the lab’s collaborators across the country have also seen, Ms. Chinnici said. But the high amount of rain this year could have contributed.
Why are ticks prospering nationally? The simple answer: rising global temperatures and changing weather patterns, according to the Environmental Protection Agency, which classifies Lyme disease as a “climate change indicator."
Warmer weather in northern climates has allowed ticks to spread into areas that were previously too cold. Shorter winters also increase the amount of time during which ticks are active and humans are exposed, according to the EPA.To receive more information about ticks and Lyme disease, Allegheny residents can call the Housing and Community Environment Program at 412-350-4046.