Post-Treatment Lyme Disease Syndrome in Six European Countries Using Data from the Burden of Lyme Disease (BOLD) Study.

Up to 10% of patients with Lyme borreliosis (LB) will experience symptoms that fulfill the Infectious Disease Society of America (IDSA) criteria of post-treatment Lyme disease syndrome (PTLDS). This study assesses PTLDS in the Burden of Lyme Disease (BOLD) study through clinical assessment ("PTLDS Assessed by Clinicians") and by post hoc evaluation of patient-reported outcomes, including the 36-Item Short Form Health Survey, Fatigue Severity Scale, and Cognitive Failures Questionnaire ("PTLDS Assessed by Questionnaire"). Among 242 LB cases who completed antibiotic treatment and had objective manifestations stabilized or resolved, 99 (40.9%) reported ≥1 symptom of fatigue, musculoskeletal pain, or cognitive impairment 10 months after diagnosis. Fifteen (6.2%) cases met the PTLDS criteria assessed by either clinicians or predefined questionnaire severity thresholds; four (1.7%) met both. PTLDS cases assessed by questionnaires and LB cases with persistent symptoms both reported greater symptom severity and poorer physical functioning than PTLDS cases assessed by clinicians. These exploratory findings suggest that clinician- and questionnaire-based assessments may identify partially different subsets of patients with PTLDS and either method could underestimate the proportion of patients with PTLDS.