Steere, A C, Taylor, E, McHugh, G L et al. · JAMA · 1993
Quick Summary
This study looked at 788 people referred to a Lyme disease clinic who were thought to have Lyme disease. Researchers found that only 23% actually had active Lyme disease, while 57% did not have Lyme disease at all—many of these patients had chronic fatigue syndrome or fibromyalgia instead. The main problem was that patients were being incorrectly diagnosed with Lyme disease and given antibiotics that didn't help because they didn't actually have the infection.
Why It Matters
This study is critical for ME/CFS patients because it demonstrates that Lyme disease is frequently misdiagnosed in patients who actually have ME/CFS or fibromyalgia, leading to inappropriate antibiotic treatment and delayed access to appropriate care. The findings highlight the importance of accurate serological testing and proper diagnostic criteria to distinguish Lyme disease from other conditions with overlapping symptoms. Understanding this distinction helps direct patients toward effective management strategies tailored to their actual condition.
Observed Findings
Only 23% (180/788) of referred patients had active Lyme disease; 57% (452/788) had no evidence of Lyme disease.
20% (156/788) of patients had previous Lyme disease with concurrent ME/CFS or fibromyalgia; in 49 of these, symptoms began shortly after documented Lyme disease.
45% of patients without Lyme disease had tested positive in outside laboratories but were seronegative on repeat testing in the referral clinic.
79% (322/409) of antibiotic-treated patients showed treatment failure due to incorrect diagnosis rather than antibiotic resistance.
Inferred Conclusions
Lyme disease is significantly overdiagnosed, with the majority of referred patients not meeting diagnostic criteria.
ME/CFS and fibromyalgia are the most common alternative diagnoses in patients referred for suspected Lyme disease.
Serological testing at non-specialized laboratories has high false-positive rates, contributing to misdiagnosis and inappropriate antibiotic use.
Accurate diagnostic criteria and standardized testing are essential to prevent treatment failure and harm from unnecessary antibiotics.
Remaining Questions
In the 49 patients where ME/CFS symptoms began after documented Lyme disease, what is the biological mechanism and how common is true post-Lyme syndrome?
What This Study Does Not Prove
This study does not prove that Lyme disease never causes ME/CFS-like symptoms or post-Lyme disease syndromes, only that misdiagnosis is common. It does not establish causality in the 49 cases where ME/CFS symptoms began after documented Lyme disease—temporal association does not prove causation. The cross-sectional design cannot determine whether serological false-positives reflect prior infection, cross-reactivity, or laboratory error.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
Why did outside laboratories have such high false-positive serological results—was this due to laboratory standards, cross-reactivity, or other factors?
What long-term outcomes did patients have after correct diagnosis and appropriate management for their actual condition?
How do clinical presentation patterns differ between true Lyme disease, previous Lyme disease with concurrent ME/CFS, and ME/CFS misdiagnosed as Lyme?