U of I team reveals tick distribution, disease pattern in Illinois

CHAMPAIGN-URBANA, Ill. (WCIA) — Scientists with the University of Illinois analyzed where three species of ticks are most likely to be found in the state, simultaneously identifying where residents are most likely to contract tick-borne diseases.

They tracked the lone star tick, the deer tick, and the dog tick. While all three are likely in every county in the state, some are more common in certain areas:

• Lone star tick – southern Illinois
• Deer tick – northern and central Illinois
• Dog tick – central and southern Illinois

“There are some counties where we’ve looked and we haven’t found them, but most counties that have looked for ticks have found all three species,” Rebecca Smith, a pathobiology professor at the University of Illinois Urbana-Champaign who led the new research, told the U of I News Bureau. “It’s just that some ticks are more common in the south, some are more common in the north, and the dog tick does better in central Illinois, where there is a lot of grassland and open habitat.”

These ticks, if infected, can pass along disease to humans and animals.

The lone star tick, for example, can transmit ehrlichiosis, tularemia the Heartland virus and Alpha-gal syndrome, an allergy to meat. The deer tick can transmit Lyme disease, anaplasmosis, babesiosis and Powassan virus disease (POWV), while the dog tick can transmit ehrlichiosis, Rocky Mountain spotted fever, tularemia and POWV.

To understand where these ticks might be most common, the researchers used data from the Illinois Department of Public Health, the Illinois Natural History Survey Insect Collection, the Global Biodiversity Information Facility, and iNaturalist.

They wanted to see if the tick hotspots lined up with tick disease transmission.

“Hamilton, Pope and Macon counties had the highest tick-collection numbers, each reporting 100 or more ticks,” the researchers wrote.

In Central Illinois, they noted that Macon, Piatt, Champaign and Douglas Counties are clusters for the deer tick. 1,728 cases of Lyme disease, 81 cases of anaplasmosis, and 23 cases of babesiosis were recorded from 2018 and 2022 in Illinois. The researchers said all cases were transmitted by the deer tick.

The researchers also found that Hamilton, Macon and Pope counties in southern and central Illinois had the most dog ticks.

The research team said their findings show the importance of using tick protection when outside. This includes wearing long pants, long socks, and closed-toed shoes. They also recommend spraying yourself with insecticides.

 Graduate student Abrar Hussain also contributed to the study.

You can find the full study here.