Positive Lyme Serology in Subacute Bacterial Endocarditis

Abstract

Lyme borreliosis is a multisystem inflammatory disorder caused by the tick-borne spirocheteBorrelia burgdorferi. Clinical manifestations are protean, involving the skin, joints, peripheral and central nervous systems, and the heart. However, the presentation of Lyme disease often overlaps with that of other conditions. We describe four patients from a region endemic for Lyme disease who had elevated levels of antibodies reactive toB burgdorferiand whose signs and symptoms were initially attributed to Lyme borreliosis but whose subsequent blood cultures established a diagnosis of nonspirochetal subacute bacterial endocarditis. Although immunoblots on serum samples from three of the four patients were consistent with prior infection fromB burgdorferi, a positive immunoblot does not establish active infection. Similarly, seropositivity toB burgdorferionly indicates possible exposure to this organism. The occurrence of positive serologies toB burgdorferiin the presence of other diseases can lead to diagnostic confusion. (JAMA. 1990;264:2916-2918)