2322. Reduced Vancomycin Susceptibility Among Pediatric Staphylococcus aureus Bloodstream Infections

Abstract

BackgroundReduced vancomycin susceptibility (RVS) is considered to be present when the minimum inhibitory concentration (MIC) is equal to 2 µg/mL. RVS Staphylococcus aureus (SA) bloodstream infections (BSI) have been associated with worse outcomes than non-RVS BSI in adults but not been well studied in children.MethodsWe reviewed the electronic medical records of infants and children admitted to Penn State Children’s Hospital with ≥1 blood culture positive for SA from 2005 to 2015. We abstracted demographic information, potential risk factors, laboratory results and clinical outcomes. We defined RVS as a vancomycin MIC = 2 µg/mL as determined by the clinical microbiology laboratory at the time of the infection. We used Chi square and Wilcoxon rank-sum tests to compare patient factors for RVS and non-RVS infections. Using a logistic regression adjusted for year and the presence of an infection-related complication, we calculated the odds of treatment failure for children with RVS and non-RVS BSI. For children with a central line in place at the time of the first positive culture, we also calculated the odds of treatment failure adjusted for year, presence of a complication and line removal. We defined treatment failure as death within 30 days of the first positive culture, recurrence of SA BSI within 30 days or a duration of bacteremia > 3 days.ResultsOf the 216 identified pediatric SA BSI, 139 (64%) had RVS: RVS was present in 63% of MSSA BSI and 65% of MRSA BSI, P = 0.835. There was no difference in age, sex, and racial distributions among children with RVS vs. non-RVS BSI. Similarly, hospitalization in the prior year, surgery within the prior 30 days, the presence of an underlying comorbidity or use of immunosuppressing medications were not more common for RVS vs. non-RVS BSI. RVS was not associated with an increased risk of treatment failure overall, odds ratio (OR)=1.34 (95% confidence interval: 0.71, 2.55), but did increase the odds of treatment failure if an indwelling central venous catheter was present and not removed, OR=3.14 (1.16, 8.54).ConclusionRVS is common among pediatric SA BSI. For central line associated SA BSI, RVS was associated with increased odds of treatment failure compared with non-RVS infections if the line was retained.Disclosures All authors: No reported disclosures.