The one study failing to confirm the success of retreatment was limited by inclusion of patients ill for 4.7 years and patients ill despite 3 previous courses of antibiotics.[1]

References

1. Klempner MS, Hu LT, Evans J, Schmid CH, Johnson GM, Trevino RP, Norton D, Levy L, Wall D, McCall J, Kosinski M, Weinstein A. Two controlled trials of antibiotic treatment in patients with persistent symptoms and a history of Lyme disease. N Engl J Med. 2001 Jul 12;345(2):85-92.