Kentucky Deer Ticks Expanding: Over 50% of Counties Affected
Deer ticks capable of transmitting Lyme disease are now established in more than half of Kentucky counties, signaling an expanding geographic risk.
This shift has important implications for clinicians and patients in regions not traditionally considered high-risk.
Widespread Tick Distribution
Researchers collected ticks from 794 hunter-harvested white-tailed deer, as well as from black bears and field biologists.
Combining new findings with prior data, investigators determined that Ixodes scapularis ticks are present in at least 59 Kentucky counties—more than 50% of the state.
This indicates widespread and growing establishment of deer ticks.
Evidence of Lyme Bacteria
Among ticks tested, approximately 11% were infected with Borrelia burgdorferi, the bacteria responsible for Lyme disease.
Notably, the presence of B. burgdorferi in Kentucky contrasts with some neighboring states where prior studies failed to detect the pathogen.
Rising Human Cases
Although reported Lyme disease cases remain relatively low, they are increasing:
- 5 cases per year (2006–2012)
- 14.25 cases per year (2013–2016)
This upward trend suggests expanding risk, with the possibility of underreporting.
Why This Matters
Tick expansion into new regions can lead to delayed recognition of Lyme disease.
Clinicians in emerging areas may be less likely to consider Lyme disease, especially when:
- Patients lack a known tick bite
- Classic rash is absent
- Symptoms are nonspecific
This creates a risk of missed or delayed diagnosis.
Public Health Implications
The authors emphasize the need for increased public health awareness and prevention efforts in Kentucky.
As tick populations expand, education around tick exposure, prevention, and early recognition becomes critical.
Clinical Takeaway
Lyme disease risk is expanding beyond traditional endemic regions. Clinicians in Kentucky and other emerging areas should consider Lyme disease in patients with compatible symptoms, even when local case numbers appear low.
Related Articles:
More than 50% of mice in Kentucky infected with Lyme bacteria
CDC advises doctors to consider Lyme disease in emerging states
Evidence of Lyme disease in the Southeast
References:
- Lockwood BH, Stasiak I, Pfaff MA, Cleveland CA, Yabsley MJ. Widespread distribution of ticks and selected tick-borne pathogens in Kentucky (USA). Ticks Tick Borne Dis. 2018.
- Eisen RJ, Eisen L, Beard CB. County-scale distribution of Ixodes scapularis in the United States. J Med Entomol. 2016.
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
I apologize for the double message. 2 weeks ago, my daughters and dog and I got mobbed by deer ticks in Woodford Co. I am curious to see how widespread incidence of Lyme had been found to be.
The number of deer ticks carrying disease continues to grow in include Colorado. Doctors disagree on how many. We do not have enough entomologist with boots on the ground in Colorado to understand how many.
This is referring to Woodford County, Kentucky, not Colorado.
Thanks for the clarification.
My husband pulled a tick off his side yesterday in Franklin County Ky.and by evening had a palm sized circular red rash around bite area. No history of tick bite allergy prior. Doc offices closed so I made him go to urgent treatment center where nurse practioner was mostly unconcerned but did give him a prophylactic one time dose of Doxycycline. Tonight rash is larger and he is nauseated. No fever or aches.
A single 200 mg dose of doxycycline has been advised for a tick bite and not a rash. I encourage anyone with a rash the size of a palm to get a second opinion.
Diagnosis of tick-borne disease is no walk in the park. Anyone pulling a tick off themselves is well advised to keep the tick. If you have the tick, testing is relatively easy and inexpensive. Be proactive by wearing a tick repellent designed specifically for ticks, and talk to your friends and neighbors about being tick aware. Stay safe out there!