Researchers at the University of Illinois have mapped areas in the state where ticks carrying Lyme disease are most prevalent. The study, based on data from 2005 to 2016, highlights northern regions as key risk zones. This information aims to inform public health strategies to prevent tick-borne illnesses.
A new study published in the Journal of Medical Entomology has pinpointed hotspots for blacklegged ticks, the primary vectors of Lyme disease, across Illinois. Led by University of Illinois entomologist and wildlife disease ecologist Brian F. Allan, the research analyzed over 1,000 ticks collected from 2005 through 2016. These specimens were tested for the bacterium Borrelia burgdorferi, which causes Lyme disease.
The findings reveal that the highest concentrations of infected ticks occur in the northern part of the state, particularly in counties surrounding Chicago, such as Cook, Lake, and McHenry. "This map can help guide public health efforts to target prevention and surveillance where they're needed most," Allan said in a university press release. The study used ecological niche modeling to predict tick distribution based on environmental factors like temperature, humidity, and land use.
Illinois has seen a rise in tick-borne diseases over the past decade, with Lyme disease cases increasing from fewer than 50 annually in the early 2000s to over 200 by 2016, according to state health department data cited in the research. The expansion of blacklegged ticks into the Midwest is attributed to warming temperatures and changes in wildlife habitats, which allow deer—a key host for the ticks—to thrive in suburban areas.
The hotspots identified include forested suburbs and nature preserves near urban centers, where human-tick encounters are frequent during outdoor activities. Researchers noted that while southern Illinois has fewer ticks, the northern infestation poses a growing public health concern. "Awareness is key; people should check for ticks after being outdoors, especially in these high-risk areas," Allan advised.
This study builds on previous work showing ticks moving northward due to climate change. Public health officials in Illinois plan to use the map for targeted education campaigns and increased monitoring. No specific incidence rates beyond state totals were provided, but the research emphasizes the need for vigilance in affected regions to curb disease spread.