Episode 556: Solving Lyme Diagnostics and Discovering New Tick-Borne Pathogens with Dr. Bobbi S. Pritt

Dr. Bobbi S. Pritt joins Tick Boot Camp Podcast for a scientific deep dive into Lyme disease diagnostics, co-infections, and emerging tick-borne pathogens. Dr. Pritt is Professor and Chair of Laboratory Medicine and Pathology at Mayo Clinic and Director of the Clinical Parasitology Laboratory in Rochester, Minnesota. An internationally recognized expert in vector-borne diseases, she is globally known for discovering new tick-borne pathogens—including Borrelia mayonii and Ehrlichia muris eauclairensis—and for advancing cutting-edge molecular and metagenomic diagnostic testing used nationwide. This episode offers essential clarity for anyone navigating Lyme disease, unexplained symptoms, or confusing test results. Dr. Pritt explains why standard tests often miss early Lyme, how PCR and molecular tools can detect active infection, and what metagenomic sequencing may offer for more accurate and comprehensive diagnostics in the future. Episode Summary Dr. Pritt breaks down how Lyme and other tick-borne diseases are detected through antibody testing, PCR, tissue analysis, and cutting-edge molecular methods. She explains how her lab discovered multiple new pathogens in the upper Midwest, the role of tick species in disease transmission, and why co-infections complicate diagnosis. This conversation also explores geographic spread, climate change, tick behavior, and the strengths and limitations of today’s test algorithms. Key Topics • Discovery of Borrelia mayonii as a second cause of Lyme disease in the U.S. • Identification and characterization of Ehrlichia muris eauclairensis • Geographic hotspots and why the upper Midwest produces unique pathogens • Tick species differences: blacklegged vs. lone star ticks and their hunting strategies • Co-feeding in ticks and its role in pathogen evolution • Why early Lyme tests often return false-negative results • The science behind false positives and cross-reactivity • PCR advantages and limitations for detecting Borrelia • When skin biopsies can outperform blood tests • Differentiating Lyme, B. miyamotoi, Anaplasma, Babesia, and Powassan virus • When clinicians should order a full tick-borne disease panel • How climate and ecological changes drive new tick-borne threats • The promise of metagenomics and immune-signature diagnostics What You’ll Learn • Why current Lyme testing algorithms struggle in early infection • How new tick-borne pathogens are discovered and validated • Why lone star ticks are more aggressive and changing regional risk • When and why molecular testing is more effective • What symptoms point to co-infections needing additional testing • Why doxycycline is not effective for certain pathogens like Babesia • How metagenomic sequencing could identify every pathogen in a single sample • Where diagnostic innovation is heading and what patients can expect