2326. Necessity of Anaerobic Blood Cultures for Identification of Pediatric Bloodstream Infections

Abstract

BackgroundThere is conflicting evidence in the literature on the necessity of anaerobic blood cultures for the diagnosis of pediatric bloodstream infections. Here we investigated the utility of anaerobic blood culture bottles in addition to aerobic blood culture bottles for the recovery of microorganisms in pediatric blood specimens.MethodsA retrospective review of positive blood culture records was performed for culture results reported from January 2016 to December 2017. Blood cultures from pediatric patients (<18 years of age) performed at the University of Wisconsin Hospital and Clinics were included in the analysis. Variables collected included patient demographics, volume of blood cultures, microorganism identification, and time-to-positivity (TTP).ResultsOf 4280 pediatric blood cultures collected during the study period, a total of 266 were positive (6.2%). Of these, 224 had been inoculated into both aerobic and anaerobic bottles, while 42 had only been inoculated into aerobic bottles. For the cases where both aerobic and anaerobic bottles were both inoculated, 100 (44.6% of 224) were positive in both bottles, 76 (33.9%) were positive only in the aerobic bottle, and 48 (21.4%) were positive only in the anaerobic bottle. The mean TTP for aerobic and anaerobic bottles was 22.6 and 21.5 hours, respectively. In the 100 cases where both bottles were positive, the same organism was identified in all but 4 cases. Among the 48 cases with only positive anaerobic bottles, the most commonly isolated genera were Staphylococcus (N = 24, 50%; n = 11 S. aureus), Bacteroides (n = 5, 10%), and Enterococcus and Escherichia (each n = 3, 6%).ConclusionOur findings demonstrate that anaerobic blood cultures are necessary to gain a complete understanding of infection status in pediatric patients. This supports the current consensus for adult blood cultures, stating that both aerobic and anaerobic bottles should be inoculated. While it is often more difficult to obtain sufficient blood volumes from pediatric patients, performance of anaerobic culture should be encouraged when possible.Disclosures All authors: No reported disclosures.