Episode 568: Lyme Disease Testing Is Failing Patients: Dr. Liz Horn Explains Why (And What Comes Next)

🎙️ Episode Summary: Lyme Testing Is Failing Early Patients In this critical episode with special guest co-host Ali Moresco, we sit down with Dr. Liz Horn, Principal Investigator of the Lyme Disease Biobank, to break down her latest research: 👉 Evaluation of standard and modified two-tiered testing algorithms using well-characterized early Lyme disease samples This study takes a hard look at the current FDA-cleared Lyme testing system — and the findings are clear: 👉 Most early Lyme disease cases are being missed Dr. Horn explains why this is happening, what it means for patients, and why clinical judgment — not just testing — must guide early diagnosis and treatment. 🔬 The Study at the Center of This Episode 📄 View Dr. Liz Horn’s Research Publications 📊 Study Focus: Compared Standard Two-Tier Testing (STTT) vs Modified Two-Tier Testing (MTTT) Used real-world patient samples from early Lyme cases Evaluated four FDA-cleared diagnostic algorithms Focused primarily on patients within the first ~3 weeks of symptoms 🚨 Key Finding: Early Lyme Testing Is Deeply Flawed Only 22–36% of early Lyme cases tested positive That means 64–78% of cases were missed Most people with early Lyme disease will test negative 📌 Easy-to-share summary for doctors and patients: New Bay Area Lyme Foundation Study Shows Common FDA-Cleared Lyme Tests Miss 64–78% of Early Cases 🧠 Why These Tests Fail Current tests detect antibodies, not the bacteria itself The immune system needs time to produce detectable antibodies Early infections often test negative because the immune response has not developed yet The two-tier system adds additional opportunities for false negatives 👉 Core issue: Testing measures the body’s response, not the infection ⏱️ The Critical Timing Problem Within 1 week of symptoms, tests are almost always negative Around 2 weeks, detection improves slightly After 3–4 weeks, sensitivity increases but is still unreliable Testing does not become fully accurate at any point 👉 Key insight: Testing remains inconsistent even after the early window 🎯 Even “Classic” Lyme Cases Are Missed Patients with erythema migrans (EM rash) often tested negative Very few patients present with a classic bullseye rash A visible rash does not guarantee a positive test result 👉 Key takeaway: You can have Lyme and still test negative ⚠️ Major Issue: Test Inconsistency The same patient can receive different results depending on the test used One algorithm may detect Lyme while another misses it Results depend on timing, immune response, and test design 👉 Result: Testing cannot reliably confirm or rule out Lyme disease 🧍‍♂️ Who Actually Tests Positive? Patients with more symptoms were more likely to test positive Longer duration of illness increased likelihood of detection Stronger immune responses improved test sensitivity 👉 Translation: Testing tends to detect later-stage immune response, not early infection 💊 After Treatment: Testing Becomes Even Less Useful This study focused on early Lyme within the first ~3 weeks, where testing already performed poorly At approximately 3 months post-treatment, less than 5% of patients who still had an active infection tested positive These patients were originally diagnosed with early Lyme and many continued to have symptoms consistent with active or ongoing infection 👉 Why this happens: Antibiotics can suppress antibody production The immune response may no longer be detectable The bacteria may persist in tissues rather than circulating in blood 👉 Critical takeaway: Patients may still have an active infection or ongoing disease process and test negative 👉 Bottom line: Testing is unreliable early in infection Testing remains unreliable after treatment A negative test does not rule out Lyme disease at any stage 🧬 Another Challenge: Lyme Leaves the Blood Borrelia bacteria can move into tissues Blood-based tests may miss active infection Direct detection becomes more difficult over time 👉 This is why antibody testing is used, despite its limitations 🧩 Bigger Insight From This Study Current Lyme testing cannot reliably diagnose early infection Diagnosis must include symptoms, exposure history, and clinical judgment Over-reliance on testing leads to missed diagnoses and delayed care 🚀 What Comes Next (Hope from the Research) Development of direct detection tests that identify the bacteria Cell-free DNA testing approaches AI and machine learning diagnostics Multiplex testing targeting multiple markers Urine-based diagnostic innovations 👉 These advances aim to replace outdated antibody-based testing 🧑‍⚕️ Education Gap (Major Takeaway) Many clinicians are not trained on the limitations of Lyme testing Negative tests are often incorrectly used to rule out disease This contributes to delayed diagnosis and treatment 📚 Resource for clinicians and patients: VectorWise CME – Lyme Disease Education 💡 What This Means for You A negative test does not rule out Lyme disease Early symptoms are more important than lab results Treatment decisions should not rely solely on testing Follow-up care remains essential even after treatment 👉 Most important: Trust your symptoms and advocate for care 💚 Final Message This study confirms what many patients already experience: The testing system is flawed Early infections are frequently missed Patients can remain sick while testing negative But progress is happening. 👉 Better diagnostics are on the horizon You are not alone. Your experience is real.Healing is possible. 🎧 Continue Learning 👉 Explore Tick Boot Camp Podcast Episodes