Background

Lyme disease (LD), caused by Borrelia burgdorferi, is the most commonly reported tick-borne disease in the United States and Europe. Recent studies suggest that 300,000 cases of LD may occur in the United States each year. Antibody-based diagnostics for LD are widely utilized in clinical practice, and the Centers for Disease Control and Prevention (CDC) recommends a 2-tier approach for serologic testing. The detection of antibodies to B. burgdorferiis highly specific and sensitive in patients with late manifestations of LD; however, the sensitivity in patients with early LD is unsatisfactory (29%–40%). Direct diagnostic testing using culture or nucleic acid amplification on peripheral blood samples also has low sensitivity (≤50%) for early LD. Thus, the diagnosis of early LD is