Recurrent Staphylococcus aureus bacteremia: Pulsed-field gel electrophoresis findings in 29 patients

To identify risk factors for relapse among 309 prospectively identified cas es of Staphylococcus aureus bacteremia, patients with recurrent S. aureus b acteremia were identified, and pulsed-field gel electrophoresis (PFGE) was performed on isolates from both episodes. PFGE banding patterns from both i solates were identical in 23 patients, consistent with relapsed infection. Patients with PFGE-confirmed relapse were more likely by both univariate an d multivariate analyses to have an indwelling foreign body (odds ratio [OR] = 18.2, 95% confidence interval [CI] = 7.6-43.6; P < .001), to have receiv ed vancomycin therapy (OR = 4.1, 95% CI = 1.5-11.6; P = .008), or be hemodi alysis-dependent (OR = 4.1, 95% CI = 1.8-9.3; P = .002) than patients who d id not develop recurrent bacteremia. These results suggest that recurrent e pisodes of S. aureus bacteremia are primarily relapses and are associated w ith an indwelling foreign body, receiving vancomycin therapy, and hemodialy sis dependence.