The prime season for tick bites is underway, and people in the region have the highest odds in the state of becoming a meal and contracting the illness Lyme disease.
Maps from the Centers for Disease Control and Prevention, Indiana State Department of Health and Purdue University show Lyme disease in the state is concentrated in Northwest Indiana, said Catherine Hill, associate professor in the Department of Entomology at Purdue University in West Lafayette and a medical entomologist with the Purdue Extension Service.
"Human cases of Lyme disease have been detected in every county in the state," she said, calling the risk "elevated" in the region.
Researchers can't explain why. One possible reason is the dense population in the area, Hill said.
She said it is easy to sensationalize Lyme disease and does not want to scare anyone, but it is more common than West Nile virus, which is transmitted by mosquitoes.
Ticks transmit Lyme disease when they're in the nymph stage, a part of the life cycle that comes in spring and early summer, Hill said.
"They're really tiny ... the size of a freckle," she said.
They crawl to the edge of vegetation, such as tall grass, and wait for a host. They can sense body heat and the odor of breath, so when a person or animal brushes against the vegetation, the tick clings and takes a blood meal, Hill said.
People should check themselves for ticks after spending time outdoors, particularly in the woods, in a yard or near tall vegetation.
Ticks should be removed only with tweezers, pulled straight out at the base of the mouth, where it meets human skin.
"A tick removed in the first 48 hours usually doesn't require any type of treatment, unless you see a rash," said Dr. Claude Foreit, president of Franciscan Physician Network.
Ticks discovered lingering after that should be removed, and the person should visit a primary care physician as soon as possible, Foreit said.
There were 81 confirmed cases of Lyme disease in Indiana in 2011, he said. Many more patients visit doctors for suspected Lyme disease.
"The majority are dog ticks or (lone) star ticks, and they don't carry the disease," Foreit said.
Up to 70 percent of people bitten and infected by the black-legged tick will see a rash resembling a bulls eye. Those who don't have the rash but experience other symptoms, such as headaches and joint pain, can undergo tests to determine a Lyme diagnosis, Foreit said.
If caught early enough, antibiotics can treat the condition.
Some people have late-onset Lyme disease, with symptoms emerging weeks, months or years after the bite. They can have joint pain, damage to their heart muscle, damage to their nervous system and more, Foreit said.