More than 50% of mice in Kentucky infected with Lyme bacteria


In their study, Buchholz and colleagues, from Western Kentucky University, found that more than half of the mice in Kentucky tested positive for Borrelia burgdorferi. They also discovered that the prevalence of B. burgdorferi was higher in tissue than in blood – a finding consistent with other studies.

“Overall prevalence of B. burgdorferi in mammals examined by blood sampling was 21.8%, while prevalence in tissues was 63.5%,” writes Buchholz.

The prevalence rates of infected mammals was similar to those in other southeastern U.S. states. Studies in Georgia, Florida and South Carolina [2] have reported the prevalence to be 6.5% and 41.8%. Meanwhile, 25% to 37% of the small mammals in Virginia are infected with B. burgdorferi [3], according of Buchholz.

Kentucky has long been considered to be a non-endemic state, but Buchholz’s findings suggest that Kentucky residents may, in fact, be at a greater risk of contracting Lyme disease than initially thought.

“The presence of B. burgdorferi in rodent species in south-central Kentucky ostensibly poses a risk for B. burgdorferi to be vectored to and cause Lyme disease in humans,” writes Buchholz.

The numbers of human cases of Lyme disease in Kentucky was lower than expected based on the number of infected mammals. Buchholz explains that “one set of hypotheses suggests an anthropogenic cause such as under- and misreported cases, while the other set focuses on ecology.”

Nevertheless, the study documents that people in Kentucky are at risk of contracting Lyme disease.



  1. Buchholz MJ, Davis C, Rowland NS, Dick CW. Borrelia burgdorferi in small mammal reservoirs in Kentucky, a traditionally non-endemic state for Lyme disease. Parasitol Res. 2018.
  2. Oliver JH, Jr., Lin T, Gao L, et al. An enzootic transmission cycle of Lyme borreliosis spirochetes in the southeastern United States. Proc Natl Acad Sci U S A. 2003;100(20):11642-11645.
  3. Sonenshine DE, Ratzlaff RE, Troyer J, et al. Borrelia burgdorferi in eastern Virginia: comparison between a coastal and inland locality. Am J Trop Med Hyg. 1995;53(2):123-133.

8 Replies to "More than 50% of mice in Kentucky infected with Lyme bacteria"

  • Kimberly Anderson
    04/13/2020 (11:32 am)

    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?

    • Dr. Daniel Cameron
      04/14/2020 (7:17 pm)

      Your daughter should be evaluated. Lyme disease should be considered even without a rash even if the tests are normal.

  • Gretchen B
    04/26/2019 (10:34 pm)

    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.

  • Christi White
    09/14/2018 (4:48 am)

    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!

  • Graham Hickling, University of Tennessee
    03/09/2018 (4:31 am)

    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.

    • Dr. Daniel Cameron
      03/09/2018 (10:58 am)

      Thanks for sharing. Studies of mice in New York from one location showed the tick borne infections were prevalent across a broad area.

    • Vicki P.
      06/27/2018 (6:46 pm)

      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.

      • Dr. Daniel Cameron
        06/27/2018 (9:02 pm)

        Thanks for sharing your frustration. The paper addressed in my Lyme Disease Science blog adds evidence that there is a problem in Kentucky.

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