FOR IMMEDIATE RELEASE
New Bay Area Lyme Foundation Study Shows Common FDA-Cleared Lyme Tests Miss 64-78% of Early Cases, Underscores Urgent Need for Improved Diagnostics
Research published in the Journal of Clinical Microbiology
PORTOLA VALLEY, Calif., April 21, 2026 –Bay Area Lyme Foundation, a national nonprofit and leading sponsor of tick-borne disease research in the US, today announced the publication of new research in the Journal of Clinical Microbiology based on data from its Lyme Disease Biobank. The study found that the commonly used FDA-cleared diagnostic testing methods available to providers and major national diagnostic laboratories are highly insensitive and miss 64-78% of early Lyme disease cases, including those who present with the characteristic erythema migrans (EM) Lyme rash.
“This study demonstrates that common two-tiered Lyme tests, utilized for decades, often fail to detect early Lyme disease and are leaving patients behind, highlighting a critical need for improved medical education on the limitations of current diagnostics,” said Liz Horn, PhD, MBI, Principal Investigator of Lyme Disease Biobank and lead author of the study. “Our findings also add to the evidence that improved diagnostics, ideally those that directly detect the bacteria that cause Lyme disease, are urgently needed.”
This large-scale, head-to-head study comparing 2 standard two-tiered testing (STTT) and 2 modified two-tiered testing (MTTT) diagnostic algorithms (the commonly used Lyme disease diagnostic algorithms) confirms that the sensitivity of two-tiered testing algorithms is low among patients with early infection. For the 107 early Lyme disease cases evaluated, the various testing algorithms missed 64-78% of early Lyme cases. Overall, only 39% (42/107) of participants with early Lyme disease were STTT or MTTT positive by any of the 4 algorithms.









