Pa. in peak season for number of ticks carrying Lyme disease

While most Lyme disease cases are confirmed in the summer, October and November are when the number of adult ticks carrying Lyme disease is highest and they are most active, according to the state Department of Environmental Protection.

“The adult ticks are emerging now and they are here to do two things – find a blood meal and a mate,” said Christian Boyer, DEP’s tick specialist.

Deer, humans and other mammals are ticks’ favorite targets for the blood meals.

The CDC ranked Pennsylvania as having the highest number of confirmed Lyme disease cases in the country in 2018. If untreated, Lyme disease carried by blacklegged ticks can cause severe symptoms that affect the heart, nervous system and joints.

In the summer, when more people are outdoors wearing less clothing, they are often bitten by blacklegged nymphs, young ticks about the size of a poppy seed.

But when the weather grows colder, the ticks hole up in leaf litter instead of hibernating, Boyer said. Ticks are less active when the temperature falls below 40 degrees, but they will emerge on those warmish days of winter when temperatures climb to 45 degrees or more. That’s when there’s a good possibility that a tick will end up on a casual walker, Boyer added.

About 51% of the blacklegged ticks in Southwestern Pennsylvania carry Lyme disease, according to the DEP.

To increase surveillance on its properties and alert staff and students, Penn State’s Veterinary Entomology Laboratory launched its Tick Safe surveillance program earlier this year in State College.

Penn State is developing a baseline study of the tick population in Centre County, said Karen Poh, a postdoctoral scholar working with the program.

Tick Safe has surveyed hiking trails, open forest and brushy areas for ticks.

“Ticks were found on the trail, even in the center of trail,” Poh said, noting that the center parts of trails are generally considered to be the safest places to walk because ticks are less commonly found there.

To guard against tick bites, Boyer and Poh advise people to apply insect repellent containing diethyltoluamide or DEET; tuck pants into boots or socks; wear light clothing; check for ticks on your body, especially behind your knees, groin and hairline areas; and take a shower promptly after walking outdoors.

Outdoor clothing can be tossed in a dryer to kill any ticks. They also can be treated with the chemical permethrin to guard against ticks.