425: RISK FACTORS FOR PERSISTENT S AUREUS BACTEREMIA IN PEDIATRIC PATIENTS: A SINGLE-CENTER COHORT STUDY

Abstract

Introduction: Staphylococcus aureus is a leading cause of infection-related hospitalization in children and accounts for approximately 23% of pediatric bacteremia. Persistent S. aureus bacteremia (SAB) is associated with worse outcomes, but there is limited understanding of the risk factors for sustained infection in children. Our objective was to identify risk factors associated with persistent SAB in our pediatric population. Methods: This was a single-center study using an established biorepository of children with S. aureus infection. Patients with at least one S. aureus positive blood culture were included. Persistent SAB was defined as positive blood cultures on 2 or more consecutive hospital days and at least 24 hours apart. Characteristics of patients with and without persistent SAB were compared using Fisher’s exact test, Wilcoxon rank sum test, and Wilcoxon rank sum exact test. Results: Of 65 patients included in the study, 38 (58%) had persistent SAB. The median age was 8.7 years, 65% were male (n=42) and 85% were white (n=54). 95% (n=62) had community-onset bacteremia, 64% (n=42) had infection caused by a methicillin-susceptible S. aureus (MSSA) isolate, and 57% (n=57) had another site of infection (e.g., abscess or bone/joint). Only 14% (n=9) of patients required ICU care. Of those, 67% (n=6) were caused by an MRSA isolate. Patients with persistent SAB had shorter duration to culture positivity than those without persistent SAB: 16 hours (IQR, 4-20h) vs. 20 hours (IQR, 16-25h) (p=0.017); and longer time to source control: 43 hours (IQR, 21-66h) vs. 17 hours (IQR,13-22h) (p=0.011). Conclusions: Our findings reveal that persistent SAB is associated with shorter time to culture positivity and longer time to source control, suggesting that a higher and sustained bacterial burden contributes to persistent infection. Interestingly, we found higher rates of persistent SAB (58%) and SAB due to MSSA (64%) than previously reported. This may be due to a combination of factors including an inconsistent definition of persistent bacteremia across studies, regional variability in S. aureus virulence, differences in the racial and ethnic diversity, and potential sampling bias. Further analysis of laboratory values, antibiotic use, chronic and co-occurring conditions of our cohort are warranted and pending.