1427. Treatment of Children with Acute Hematogenous Osteomyelitis and Staphylococcus aureus Bacteremia: Impact of Severity of Illness on Antimicrobial Therapy

BACKGROUND: There is limited evidence-based guidance for the treatment of children with acute hematogenous osteomyelitis (AHO) and concurrent Staphylococcus aureus bacteremia (SAB). Current guidelines emphasize the need for parenteral antibiotics in the setting of SAB, but optimal duration of parenteral therapy in this setting remains unclear. We examined the utility of a Severity of Illness (SOI) score to provide guidance for antimicrobial use in this setting. METHODS: We retrospectively studied children with AHO from 2009–2017, employing a clinical practice algorithm and previously validated SOI to assess the incidence and treatment implications of SAB in AHO. Data collected included demographics, antimicrobial therapy, and response to treatment. Cohorts were categorized according to SOI as follows: mild (0–3); moderate (4–7); and severe (8–10), and compared utilizing one-way ANOVA and Kruskal–Wallis tests for continuous variables, and chi-square test for categorical data. RESULTS: Among 466 children diagnosed with AHO, 274 (58.5%) were culture positive for Staphylococcus aureus, with SAB noted in 209 (44.8%) individuals. Among children with SAB, 72, 81, and 56 children had SOI scores classified as mild, moderate, and severe, respectively. There were 41 of 72 (57.7%) children with mild illness who were managed with clindamycin alone, clindamycin followed by β-lactam, or β-lactam alone, compared with 36 of 81 (44.4%) with moderate illness, and 3 of 56 (5.4%) with severe illness. Median parenteral antibiotic durations per SOI cohort were 4.7 days, 10.4 days, and 24.7 days, respectively. Greater SOI was associated with longer hospitalization, prolonged bacteremia, more surgeries, increased vancomycin use, greater number of antibiotic combinations, and longer total duration of antibiotics. CONCLUSION: Treatment of AHO with SAB should be tailored to the severity of illness in the affected child. A “one size fits all” approach may expose children to unnecessarily prolonged parenteral antibiotic courses, as well as suboptimal and potentially toxic regimens. Our study demonstrates the utility of an SOI to help guide antibiotic decisions in the setting of AHO with SAB. Additional studies are needed to further delineate optimal parenteral antibiotic durations in AHO with SAB. [Image: see text] [Image: see text] [Image: see text] DISCLOSURES: All authors: No reported disclosures.