More Evidence of Lyme Disease in the Southern United States

Lyme disease has traditionally been considered a Northeastern and Midwestern illness. However, growing evidence suggests that the geographic risk may be broader than previously recognized.

Ticks capable of carrying Borrelia burgdorferi are now found across a large portion of the United States, including many Southern states. :contentReference[oaicite:0]{index=0}

Ticks Are Present — But Risk Looks Different

The blacklegged tick (Ixodes scapularis), the primary vector for Lyme disease, is widely distributed throughout the eastern United States, extending into the South.

However, infection rates in ticks tend to be lower in Southern regions compared to the Northeast. :contentReference[oaicite:1]{index=1}

This difference may be related to ecology rather than absence of disease.

• In the North, ticks feed more often on mice, which efficiently transmit Lyme bacteria
• In the South, ticks more commonly feed on reptiles, which are poor reservoirs

This shift may reduce—but not eliminate—the risk of human infection.

Evidence of Southward Expansion

Studies have documented a gradual expansion of Lyme disease into Southern regions.

In Virginia, for example, cases have increased and spread southward along the Appalachian Mountains, with new clusters emerging over time. :contentReference[oaicite:2]{index=2}

Researchers have suggested that if these trends continue, neighboring states may see increasing local transmission.

Ticks and Human Exposure

Even when infection rates in ticks are lower, exposure still occurs.

Ticks are present in parks, wooded areas, and suburban environments across the South, increasing the likelihood of human contact.

In addition, other tick-borne illnesses—such as southern tick-associated rash illness (STARI)—can resemble Lyme disease and further complicate diagnosis. :contentReference[oaicite:3]{index=3}

Why This Matters Clinically

Geographic assumptions can influence diagnosis.

If Lyme disease is considered unlikely based on location alone, cases may be overlooked—particularly in patients with atypical presentations.

As tick populations expand and environments change, clinicians may need to consider Lyme disease across a broader geographic range.

Clinical Perspective

The presence of ticks and emerging evidence of southward spread suggest that Lyme disease risk is not confined to traditional endemic regions.

While regional differences in transmission exist, they do not eliminate the possibility of infection.

Patients may benefit from understanding Lyme disease symptoms, reviewing prevention strategies, and considering tick-borne coinfections when symptoms follow tick exposure.

Key Takeaway

Lyme disease may be less common in the South—but it is not absent.

Awareness of regional variation, rather than reliance on strict geographic boundaries, may improve early recognition and care.

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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