Ticks in Kentucky: Deer Ticks, Lyme Disease, and Growing Risk

Ticks are widespread across Kentucky.
Some carry Lyme disease and other infections.
Knowing the risks can help prevent tick-borne illness.

Ticks in Kentucky include blacklegged ticks, lone star ticks, American dog ticks, and Gulf Coast ticks. Some can transmit Lyme disease or other serious tick-borne infections.

While Kentucky has historically reported fewer Lyme disease cases than many northeastern states, recent studies show that the blacklegged tick, also known as the deer tick, is present across much of the state. Other tick-borne diseases, including ehrlichiosis and spotted fever group rickettsioses, are also important concerns in Kentucky.

Deer ticks are widespread in Kentucky

Lockwood and colleagues collected deer ticks from 794 hunter-harvested white-tailed deer and 2 ticks from black bears killed by cars. An additional 6 ticks were removed from two field biologists assisting with tick collection, which took place between October 2015 and January 2017.

“We combined our data (41 new county records) with data from Eisen et al. (2016) (18 counties) which indicate I. scapularis is present in at least 59 counties,” Lockwood and colleagues wrote.

The authors concluded that the deer tick “occurs throughout Kentucky and is established in numerous counties where it had not been previously reported.”

Furthermore, the authors examined a subset of ticks and found that 11% were infected with Borrelia burgdorferi, the bacterium that causes Lyme disease. “We detected B. burgdorferi s.s. in I. scapularis at numerous sites across Kentucky despite similar studies in Tennessee failing to detect B. burgdorferi s.s. in >800 I. scapularis tested,” the authors wrote.

Do ticks in Kentucky carry Lyme disease?

Yes. The blacklegged tick, or deer tick, has been found in Kentucky and can carry Borrelia burgdorferi. Lockwood and colleagues detected the Lyme disease bacterium in deer ticks collected across Kentucky.

Although the number of reported Lyme disease cases in Kentucky remains lower than in highly endemic northeastern states, the authors noted that reported human Lyme disease cases increased from an average of 5 cases per year from 2006 through 2012 to 14.25 cases per year from 2013 through 2016.

Although reported Lyme disease incidence remains lower than in the Northeast, expanding blacklegged tick populations suggest that clinicians should remain alert for locally acquired infections.

The authors did not discuss the possibility of underreporting. However, Lyme disease may be missed when clinicians do not expect it in emerging or lower-incidence states. Patients with compatible symptoms after a tick bite should be evaluated carefully, particularly when exposure occurred in areas where blacklegged ticks are established.

What types of ticks are found in Kentucky?

Kentucky is home to several tick species of medical importance. These include:

• Blacklegged tick or deer tick (Ixodes scapularis) — the primary vector of Lyme disease in the eastern United States.
• Lone star tick (Amblyomma americanum) — associated with ehrlichiosis, STARI-like illness, tularemia, Heartland virus, Bourbon virus, and alpha-gal syndrome.
• American dog tick (Dermacentor variabilis) — associated with spotted fever group rickettsioses.
• Gulf Coast tick (Amblyomma maculatum) — found in parts of the region and associated with Rickettsia parkeri.

Patients who remove a tick may find it helpful to review tick identification resources, since different tick species are associated with different pathogens.

This means that Kentucky tick bites should not be evaluated only through the lens of Lyme disease. Depending on the tick species and clinical presentation, clinicians may also need to consider ehrlichiosis, spotted fever group rickettsioses, tularemia, STARI-like illness, and alpha-gal syndrome.

Lone star ticks are widespread in Kentucky

A 2011 Kentucky tick surveillance study by Fritzen and colleagues examined adult lone star ticks and American dog ticks collected from several animal and human hosts. The investigators found multiple pathogens in Kentucky ticks, including Ehrlichia chaffeensis, Ehrlichia ewingii, Borrelia lonestari, and several Rickettsia species.

In that study, 14.3% of ticks were positive for a Rickettsia species, 4.9% were positive for Ehrlichia chaffeensis, and 1.4% of lone star ticks were positive for Ehrlichia ewingii. One lone star tick was positive for Borrelia lonestari. The investigators did not detect Borrelia burgdorferi in the lone star or American dog ticks they tested, which is expected because those species are not the primary Lyme disease vectors.

A more recent statewide surveillance study by Pasternak and Palli collected 5,726 lone star ticks from 77 Kentucky counties from 2019 through 2020. The researchers detected Ehrlichia chaffeensis in lone star ticks from 32 counties, with a minimum infection rate of 1.8%.

These studies show that Kentucky’s tick-borne disease risk includes more than Lyme disease. Lone star ticks are abundant, aggressive biters and are associated with pathogens that can cause febrile illness after a tick bite.

Can you get ehrlichiosis in Kentucky?

Yes. Kentucky is considered an important state for ehrlichiosis risk, and the lone star tick is the primary vector for Ehrlichia chaffeensis. Ehrlichiosis can cause fever, headache, muscle aches, fatigue, low white blood cell count, low platelet count, and elevated liver enzymes.

Pasternak and Palli emphasized that Kentucky experiences some of the highest incidence rates for ehrlichiosis nationwide. Their detection of Ehrlichia chaffeensis in 32 counties supports the need for clinicians to consider ehrlichiosis in patients with fever after a tick bite in Kentucky.

When is tick season in Kentucky?

Tick activity in Kentucky varies by species and season. Blacklegged ticks may be active during cooler months, while lone star ticks and American dog ticks are most active during spring and summer.

Because Kentucky has relatively mild winters, ticks may be encountered during much of the year. People should use prevention measures during outdoor activities, especially in wooded areas, tall grass, brush, leaf litter, and areas frequented by deer or other wildlife.

Why Kentucky tick risk may be underestimated

Reported Lyme disease numbers may not fully capture the clinical burden of tick-borne disease in Kentucky. There are several reasons this may occur.

• Patients may not remember a tick bite.
• Clinicians may not consider Lyme disease or ehrlichiosis in regions viewed as lower-risk.
• Early symptoms may be nonspecific, including fever, fatigue, headache, muscle aches, and joint pain.
• Different tick species can transmit different pathogens, complicating diagnosis.
• Surveillance data may lag behind changes in tick distribution.

Lockwood concluded that “public health measures are important to prevent tick-borne diseases in Kentucky.”

What should patients and clinicians watch for?

Patients who develop symptoms after a tick bite in Kentucky should seek medical evaluation, especially if they develop fever, rash, headache, fatigue, muscle aches, joint pain, swollen lymph nodes, palpitations, facial weakness, or neurological symptoms.

Clinicians should consider the possibility of multiple tick-borne diseases. A patient bitten by a blacklegged tick may be at risk for Lyme disease, while a patient bitten by a lone star tick may be at risk for ehrlichiosis or other tick-associated illnesses.

Because early symptoms overlap, diagnosis should be based on exposure history, symptoms, physical findings, regional tick data, and appropriate laboratory testing when indicated.

Clinical Perspective

Kentucky is no longer a state where clinicians should dismiss Lyme disease simply because it has historically been considered uncommon. The expanding distribution of blacklegged ticks, combined with widespread lone star ticks, means physicians should consider multiple tick-borne diseases when evaluating patients after tick exposure.

For patients, the key message is practical: prevention matters, tick identification can be useful, and new symptoms after a tick bite deserve timely medical evaluation.

Frequently Asked Questions

Are there ticks in Kentucky?

Yes. Kentucky has several medically important tick species, including blacklegged ticks, lone star ticks, and American dog ticks. Recent studies show that these ticks are widely distributed across the state.

What types of ticks are in Kentucky?

Important ticks in Kentucky include the blacklegged tick, lone star tick, American dog tick, and Gulf Coast tick. Each species may be associated with different tick-borne diseases.

Do ticks in Kentucky carry Lyme disease?

Yes. Blacklegged ticks in Kentucky can carry Borrelia burgdorferi, the bacterium that causes Lyme disease. One study detected B. burgdorferi in blacklegged ticks collected across Kentucky.

Is Lyme disease common in Kentucky?

Kentucky reports fewer Lyme disease cases than highly endemic northeastern states, but reported cases have increased, and blacklegged ticks are established in many counties. Lyme disease should be considered when symptoms and exposure history are compatible.

When is tick season in Kentucky?

Tick activity can occur during much of the year in Kentucky. Lone star ticks and American dog ticks are most active during spring and summer, while blacklegged ticks may also be active during cooler months.

What diseases can lone star ticks transmit in Kentucky?

Lone star ticks in Kentucky are associated with ehrlichiosis and may also be linked to STARI-like illness, tularemia, Heartland virus, Bourbon virus, and alpha-gal syndrome. They are aggressive biters and are common in the region.

Clinical Takeaway

Ticks in Kentucky are not limited to one species or one disease. Blacklegged ticks are established in many counties and can carry Borrelia burgdorferi, while lone star ticks are widespread and can transmit Ehrlichia chaffeensis and other pathogens.

The presence of infected ticks across Kentucky means clinicians should consider tick-borne diseases in patients with compatible symptoms, even when Lyme disease has historically been viewed as less common in the state.

Patients with fever, rash, fatigue, headache, joint pain, or other symptoms after a tick bite in Kentucky should be evaluated for the full range of regional tick-borne diseases.

Related Articles

Continue learning about Lyme disease and tick-borne illness risk:

More than 50% of mice in Kentucky infected with Lyme bacteria
CDC advises doctors to consider Lyme disease in emerging states
Culture evidence of Lyme disease in antibiotic-treated patients living in the Southeast
Lyme Disease Symptoms Guide
Lyme Disease Coinfections

References

1. 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;9(3):738-741.
2. Eisen RJ, Eisen L, Beard CB. County-scale distribution of Ixodes scapularis and Ixodes pacificus (Acari: Ixodidae) in the continental United States. J Med Entomol. 2016;53(2):349-386.
3. Fritzen CM, Huang J, Westby K, Freye JD, Dunlap B, Yabsley MJ, Schardein M, Dunn JR, Jones TF, Moncayo AC. Infection prevalences of common tick-borne pathogens in adult lone star ticks (Amblyomma americanum) and American dog ticks (Dermacentor variabilis) in Kentucky. Am J Trop Med Hyg. 2011;85(4):718-723.
4. Pasternak AR, Palli SR. County-level surveillance for the lone star tick, Amblyomma americanum, and its associated pathogen, Ehrlichia chaffeensis, in Kentucky. Ticks Tick Borne Dis. 2023;14(1):102072.

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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