Is Lyme Disease Common in Kentucky? Why Risk May Be Higher Than Reported
Kentucky is often considered low risk.
But Lyme bacteria are present.
And cases may be missed.
Lyme disease in Kentucky may be more common than reported.
Even in areas considered non-endemic, studies show that mice can carry the bacteria that causes Lyme disease.
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Is Lyme Disease Common in Kentucky?
Kentucky has traditionally been considered a low-risk state for Lyme disease.
However, recent research suggests that the risk may be underestimated.
The presence of infected animals indicates that Lyme disease transmission may be occurring—even when reported human cases are low.
Do Mice Carry Lyme Disease?
Yes, mice are a key reservoir for Lyme disease.
Mice do not get sick from Lyme disease, but they carry the bacteria and infect ticks that feed on them.
In a study by Buchholz and colleagues, more than half of the mice in Kentucky tested positive for Borrelia burgdorferi, the bacteria that causes Lyme disease.
Prevalence was significantly higher in tissue samples (63.5%) than in blood samples (21.8%).
This finding is consistent with other studies showing that Lyme bacteria may be easier to detect in tissue than in blood.
What This Means for Lyme Risk
High infection rates in mice suggest that Lyme disease could be circulating more widely than human case numbers indicate.
Researchers noted that human cases in Kentucky were lower than expected based on animal infection rates.
This may be due to:
- Underreporting of Lyme disease cases
- Misdiagnosis or missed diagnosis
- Differences in local ecology and tick exposure
This creates a gap between actual infection risk and reported cases.
How Kentucky Compares to Other States
The prevalence of infected mammals in Kentucky is similar to findings in other southeastern states.
- Georgia, Florida, South Carolina: 6.5%–41.8%
- Virginia: 25%–37%
This suggests that Lyme disease risk may extend beyond traditionally endemic regions.
Why This Matters
Lyme disease risk is influenced by infected hosts, not just reported cases.
If mice carry the bacteria, ticks feeding on them can become infected—and potentially transmit Lyme disease to humans.
This creates a hidden risk in areas where Lyme disease is not commonly diagnosed.
Clinical Takeaway
Lyme disease in Kentucky may be underrecognized.
High rates of infection in mice suggest that the bacteria is present and capable of spreading to humans.
Clinicians and patients should remain aware of Lyme disease—even in regions considered low risk.
References
- Buchholz MJ, Davis C, Rowland NS, Dick CW. Borrelia burgdorferi in small mammal reservoirs in Kentucky. Parasitol Res. 2018.
- Oliver JH Jr., et al. Enzootic transmission cycle in southeastern U.S. PNAS. 2003.
- Sonenshine DE, et al. Borrelia burgdorferi in Virginia. Am J Trop Med Hyg. 1995.
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
The mouse study was done entirely at WKU’s Green River Reserve, so it’s a bit of a stretch to extend the results to all of Kentucky. Nevertheless, the conclusion is probably correct: a new survey of blacklegged ticks off deer found Borrelia infection in many KY counties. https://www.sciencedirect.com/science/article/pii/S1877959X1730571X
Thanks for sharing. Studies of mice in New York from one location showed the tick borne infections were prevalent across a broad area.
We have patients from all over KY contacting us, KY Lyme Disease Association, that have confirmed Lyme disease. Our LLMD’s are fed up with KY for not doing more. We have to send patients out of state because UofL and UK continue to teach their doctors that Lyme is NOT in KY. Our whole family has Lyme and up and down our road, people have Lyme. Doctors do not recognize symptoms here and our LLMD’s are getting flooded.
Thanks for sharing your frustration. The paper addressed in my Lyme Disease Science blog adds evidence that there is a problem in Kentucky.
My 7 yr old daughter was diagnosed with Lyme disease monday september 10th 2018. I live in Trigg county kentucky in a rural area by Lake Barkley. She has the bulls eye rash in 2 places. Tomorrow we go for lab testing in a county nearby. Me and my husband are so scared we don’t know where to take her to ensure she gets the best treatment available please any advice is welcome. Thank you to anyone with help or advice for reading my comment!
I am another resident of Kentucky that has been diagnosed with Lyme . Northern Kentucky. I am sure that ticks carrying tickborne diseases are just cruising through the Ohio River Valley, which basically runs from Pennsylvania to the Mississippi river. In my area I know of almost 40 people fighting lyme or ” after damage”. We have all had to go out of state for treatment.
My granddaughter had two very small ticks on her back I got them out but the second one I don’t think I got the head out they were very itchy once I removed them the spots were still itchy but the night before last she said she was feeling dizzy while she was laying down she laid in bed half of the day which is not normal for her and last night she didn’t go to sleep until 2am the spots are swollen but no bulls eye Does this sound like a tick bite that needs medical attention?
Your daughter should be evaluated. Lyme disease should be considered even without a rash even if the tests are normal.