A new CDC study is adding to the national picture of how widely tick-related alpha-gal exposure may be affecting adults in parts of the United States. The July 2 report focused on states where lone star ticks are common and found a notably higher share of adults with antibodies linked to exposure that can precede alpha-gal syndrome, the condition associated with reactions to red meat.
CDC study found elevated alpha-gal antibody rates in 5 states
The Centers for Disease Control and Prevention published the new findings on July 2, drawing from an analysis of about 3,000 adult blood donors in 10 states. According to the CDC analysis, adults in Arkansas, Kentucky, Missouri, Tennessee and Virginia had the highest estimated prevalence of alpha-gal antibodies, at about 24% across those five states. The samples were collected from November 2024 through April 2025.
Lead study author Dr. Eleanor Saunders of the University of North Carolina-Chapel Hill told NBC News that the antibodies show prior exposure to the alpha-gal molecule, not a confirmed diagnosis of alpha-gal syndrome. That distinction matters because alpha-gal syndrome is the red meat allergy itself, while the antibody result signals that a person was likely bitten by a tick capable of transmitting the molecule. The CDC says the condition is most often associated in the United States with the lone star tick.
The report adds a new estimate to a condition that has been difficult to measure nationally. CDC materials say alpha-gal syndrome is not a nationally notifiable disease, although the agency encourages jurisdictions to report cases and uses a standardized case definition approved in 2021. Earlier CDC research estimated that roughly 450,000 Americans may have developed alpha-gal syndrome, but the new July 2026 study examined potential exposure more broadly rather than counting diagnosed cases.
For residents in the five states highlighted in the study, the clearest confirmed finding is that exposure markers were more common there than in the other states included in the analysis. NBC News reported that these five states were identified as areas already known to have high levels of lone star ticks, which aligned with the higher antibody prevalence in the blood samples.
What the study does not show is how many adults in each of those states currently have alpha-gal syndrome. The CDC study, as described by NBC News and local coverage in Missouri, reported a combined estimate for the five-state group rather than a full state-by-state diagnosis count. Public reporting also has not identified a comprehensive breakdown of affected counties or local communities within each state.
That leaves an important gap for residents and clinicians. CDC guidance says symptoms can include hives, nausea, severe stomach pain, trouble breathing, dizziness and, in some cases, anaphylaxis. The agency also notes that reactions can appear hours after eating mammalian meat or products derived from mammals, which can make the condition harder to connect to a specific meal than other food allergies.
Researchers and public health officials have been warning that alpha-gal syndrome may spread beyond its traditional footprint. Dr. Scott Commins, a co-author of the new research and an allergy specialist at the University of North Carolina, told NBC News that cases are being seen more often in Oklahoma and farther north toward the Great Lakes. He attributed that shift in part to warmer winters and deer movement into new areas, which can help ticks expand their range.
The CDC says lone star ticks are the main U.S. driver of alpha-gal syndrome, though other tick species have also been cited by advocacy groups and researchers. That broader ecological shift is one reason the new study is drawing attention even though it does not diagnose the allergy itself. The presence of antibodies may indicate a larger pool of adults with prior exposure than earlier case counts suggested.
For residents in the five highlighted states, the practical takeaway is limited but important: the study points to wider exposure, not a recommendation that symptom-free adults stop eating red meat. Saunders told NBC News the report was not meant to encourage overdiagnosis, and CDC guidance continues to center on symptoms, clinical history and antibody testing when alpha-gal syndrome is suspected. Federal tracking remains incomplete, so the full scale of diagnosed illness is still not publicly pinned down.