McLEAN — Felicia Harrison applied insect repellent containing DEET to her exposed skin before taking off on a trail run through the woods with other members of the Shady Hollow Trail Runners.
A few minutes later, Kathy Shultz checked her dog's ears and ran her fingers through his fur.
"He loves it because he thinks it's a massage," Shultz said of her dog, Rafferty.
But the steps that Harrison and Shultz the evening of June 13 at Sugar Grove Nature Center in rural McLean were to reduce the risk of increasingly prevalent illnesses.
Tickborne illnesses have been on the rise in Illinois for the past several years. While none of the runners or Shultz had removed ticks from themselves and their pets so far this year at Sugar Grove, they prefer to be safe rather than sorry.
"Be smart and figure out how to reduce your risk so you can be outside," advised Harrison of Bloomington.
"My message to people is be cautious but don't be afraid," said Ann Spence of Normal, who is nearly recovered from from Lyme disease that she got in 2003.
While it's too soon to say whether there are more ticks this year, it's likely if the trend of the past several years continues.
The reasons are numerous and are cause for concern because ticks can transmit diseases, including Lyme disease, to people and pets. Left untreated, those diseases can damage the joints, heart and nervous system.
"Ticks carry a shockingly large number of illnesses," said Steven Juliano, an Illinois State University distinguished professor of ecology.
The good news is that tickborne illnesses are treatable with antibiotics within a couple weeks of infection.
"Get to a doctor, get tested and evaluated and get treated," Juliano advised. "There is effective treatment, but the earlier you're treated, the better."
"Ticks are nasty critters, but they aren't a reason to be scared of the woods," agreed Dr. Kirsten Pieper, a Central Illinois veterinarian and trail runner. "Use common sense and enjoy nature."
The number of Illinoisans who get a tickborne illness is unknown because Illinois Department of Public Health (IDPH) only counts cases confirmed by testing.
In 2000, there were 41 confirmed cases, said IDPH entomologist Linn Haramis. By 2010, the number had increased to 200 confirmed cases, he said. The provisional total for 2016 is 348 cases.
Those include Lyme disease, Rocky Mountain Spotted Fever, Ehrlichiosis, Babesiosis and Anaplasma Phagocytophilum.
"It's been a slow, steady increase," Haramis said.
"There has been an increase in ticks and tickborne illnesses in the past two decades," said Ben Sadd, an Illinois State University assistant professor of infectious disease ecology.
"The Deer Tick is moving south (through Illinois) while the Lone Star Tick is moving north," Haramis said.
One reason could be global warming. As winters become milder, fewer ticks and the small mammals they feed on — such as mice — die during winter, said Sadd and Juliano.
"Conditions are favorable to ticks and their hosts (such as mice) when it's warm and wet," Sadd said. "Climate change could accelerate tick development, which could impact tickborne illnesses."
Loss of natural predators and increasing residential development in forested areas also mean that people and their pets are increasingly likely to share areas with deer, foxes, raccoons, rabbits and other mammals that can carry ticks.
"Forest habitat fragmentation leads to more exposure," Juliano said.
"I think we're seeing more in this area," Pieper said. "Before, we'd see Lyme disease in dogs who had traveled to Wisconsin. Now, we're seeing it in Morris and in Bloomington-Normal dogs who haven't been out of the area."
Whether there are more ticks this year and whether this will be a worse year for tickborne illnesses is suspected but isn't known yet. The mild winter and wet spring mean it's more likely that more ticks and mice survived the winter, Haramis said.
"I'm outside all the time on the trail and in the woods and they (ticks) are definitely out there," Pieper said. "But I don't know that it's worse this year. I have seen dogs test positive for Lyme disease and Rocky Mountain Spotted Fever this year."
Adult ticks are about the size of a sesame seed and nymphs are about the size of a poppy seed. Ticks sometimes are at the end of twigs, brush and tall grass and attach themselves to the legs of people who walk by and the underside of dogs.
They climb to areas that are warm and where they can remain undetected, such as the groin, armpits and scalp of humans and the underside, inside the ear and forehead of dogs.
Ticks try to borrow most of their head under the skin of their hosts to drink their blood. After they bite, they must be attached for at least four hours before they can transmit Rocky Mountain Spotted Fever and at least 18 hours before they can transmit Lyme disease, Haramis said.
Dogs who aren't treated can develop high fever, joint pain and soreness and kidney failure, Pieper said. In rare cases, Lyme disease in dogs can be fatal.
People who aren't treated can develop long-term symptoms, including joint pain, nervous system abnormalities, sleep disturbance, problems with memory and concentration, muscle twitching and heart rhythm irregularities. In rare cases, tickborne illnesses are fatal.
If your dog becomes feverish, lethargic and in pain within a few days, call his vet immediately. Antibiotic and anti-inflammatory treatment is available and most make a full recovery if the disease is caught early, Pieper said.
If you or a family member become feverish, fatigued, experience joint pain and develop a bull's-eye rash after removing a tick, see your doctor immediately. People also can be treated with antibiotics. The quicker the treatment, the more complete the recovery.
"Don't stay inside all summer," Sadd said. "But be vigilant."
"There's so much out there to enjoy," Spence said. "Go enjoy it. Just be careful."