1060. Risk Factors for Recurrent Staphylococcus aureus Bacteremia

Abstract Background Recurrent Staphylococcus aureus bacteremia (Re-SAB) occurs in 2–17% of patients with SAB within 3–12 months after resolution of the first episode. The risk factors for Re-SAB are incompletely understood. Methods Re-SAB was defined as a second episode of SAB after the resolution of the first episode occurring at least 14 days from the date of the last positive blood culture of the first episode. Using the SAB Group Prospective Cohort Study (SABG-PCS) data between January 2008 and May 2015, patients with Re-SAB were selected and compared with those without it. Pulsed-field gel electrophoresis (PFGE) was done for the clinical isolates from the Re-SAB group, and spa typing was for those from both groups. Baseline sera from patients with Re-SAB and age/race/gender matched (1:1) control subjects with SAB but without Recurrence underwent Luminex multiplex cytokine array. Results Seventy patients experienced Re-SAB (9.3%) and 686 SAB patients did not. In the Re-SAB group, 156 episodes of SAB were observed. Median time to Re-SAB was 147.5d (IQR, 76–358). Among 65 PFGE-analyzed pairs of isolates from the first and the subsequent episodes, the time to Re-SAB of <300 days was more commonly found in the PFGE-identical pairs than in the PFGE-different pairs (75.6% vs. 33.8%, P = 0.001). In the comparison of clinical factors between 56 Re-SAB patients with available data and 686 without Re-SAB, African American race, dialysis dependence, the presence of foreign body, persistent bacteremia, metastatic abscess formation, and methicillin-resistant S. aureus (MRSA) were more frequently observed in patients with Re-SAB. In a multivariate analysis to identify risk factors for Re-SAB, African American race, dialysis dependence, metastatic abscess formation, and MRSA were independent risk factors. The distribution of spa types between the two group was presented in Figure 1. Conclusion Re-SAB involves a combination of multiple factors of host, microbe, and treatment. Further laboratory investigation for any determinants in host and microbe is required. Disclosures V. G. Fowler Jr., Merck, Cerexa/Actavis, Pfizer, Advanced Liquid Logis, NIH, MedImmune, Basilea, Karius, Contrafect, Regneron, Genentech, Affinergy, Locus, Medical Surface, Inc., Achaogen, Astellas, Arsanis, Bayer, Cubist, Debiopharm, Durata, Grifols, Medicines Co, Novartis: Collaborator, Consultant and Scientific Advisor, Consulting fee, Research grant and Research support.