Blacklegged ticks carrying the bacterium that causes Lyme disease appear to be expanding south into western North Carolina, according to a US Centers for Disease Control and Prevention report published Thursday, August 13. Researchers found that about 40% of tested adult blacklegged ticks from Biltmore Forest carried Borrelia burgdorferi, a prevalence comparable with parts of the Northeast, upper Midwest and mid-Atlantic where Lyme disease is endemic. The CDC described southern Appalachia as an emerging risk area rather than an established endemic region.
The investigation followed residents' concerns about tick-borne illnesses in Biltmore Forest, a wooded town beside Asheville. Researchers collected ticks monthly at 22 residential properties from November 2024 through August 2025, while residents also submitted specimens from themselves, pets and properties. The team collected 373 ticks from 25 properties; 287, or 76.9%, were blacklegged ticks. CDC laboratories tested suitable specimens with multiplex polymerase chain reaction sequencing.
Among the blacklegged ticks tested individually, 19 of 48 adults, or 39.6%, and three of seven nymphs, or 42.9%, carried the Lyme bacterium. Investigators also detected Borrelia miyamotoi, which can cause relapsing fever, in two adults and two larval pools. Four adults carried the human-active strain of Anaplasma phagocytophilum, the bacterium associated with anaplasmosis. The authors said those additional pathogens may represent their farthest-south detection in blacklegged tick populations.
The community survey recorded 19 people from 17 households who reported at least one tick-borne disease diagnosis while living in the town. Seventeen reported Lyme disease, two babesiosis and one ehrlichiosis, with some people reporting more than one infection. However, only four provided medical records, and most diagnoses were self-reported. Infected ticks appeared across the study area, but the report did not establish a community infection rate or prove that its findings apply across the wider region.
The authors emphasized several limitations. Only 75 of roughly 600 households returned the initial survey, the sampled residential area was small, and crews collected ticks on just one to three days in most months. Collection began soon after Hurricane Helene, and researchers lacked comparable pre-storm data, leaving the storm's effect on local tick populations uncertain. Weather and environmental conditions also might have influenced the number of host-seeking ticks found on collection days.
The CDC report calls for greater clinical awareness, public education and broader tick and pathogen surveillance across southern Appalachia. It advises residents and visitors to wear protective clothing, use an Environmental Protection Agency-registered repellent and check their bodies for ticks after outdoor activity. Researchers said better recognition among primary-care, urgent-care and infectious-disease clinicians could support earlier diagnosis as health authorities determine how far the ticks and pathogens have spread.
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