Repeat infective endocarditis: Differentiating relapse from reinfection

Repeat infective endocarditis due to the same species can represent relapse of the initial infection or a new infection. We used time- based clinical criteria and pulsed- field gel electrophoresis - based molecular criteria to classify 13 cases of repeat infective endocarditis as either relapse or reinfection. The agreement between clinical and molecular criteria was imperfect ( agreement in 10 [ 77%] of 13 cases).