Impact of QuickFISH in addition to antimicrobial stewardship on vancomycin use and resource utilization in cancer patients with coagulase-negative staphylococcal blood cultures

Abstract

ObjectiveTo evaluate the impact of rapidly identifying coagulase-negative staphylococci (CoNS) from positive blood cultures combined with an established antimicrobial stewardship (AS) programme at a tertiary cancer centre. MethodsWe compared cancer patients ≥18 years old who between 01/1/13 and 12/31/13 had one or more positive CoNS blood culture(s) identified by Staphylococcus QuickFISH® (a peptide nucleic acid fluorescence in situ hybridization assay) with cancer patients ≥18 years old who had CoNS identified by standard microbiological techniques between 01/01/11 and 12/31/11 (baseline). Positive blood culture results were reported to the clinician by microbiology staff; restricted antibiotics (e.g., vancomycin) required approval by the AS team. ResultsThere were 196 baseline and 103 QuickFISH patients. Faster median time to organism identification (33 (IQR 27–46) versus 49 (IQR 39–63) hours, p < 0.001), more vancomycin avoidance (51/103 (50%) versus 60/196 (31%), p 0.002), shorter median antibiotic duration (1 (IQR 0–3) versus 2 (IQR 0–6) days, p 0.019), fewer central venous catheter (CVC) removals (14/78 (18%) versus 57/160 (36%), p 0.004), and reduced vancomycin level monitoring (16/52 (31%) versus 71/136 (52%), p 0.009) were observed in the QuickFISH group. QuickFISH implementation was predictive of a lower likelihood of antibiotic therapy prescription (OR 0.35, 95%CI 0.20–0.62, p < 0.001). Prior transplant (RR 1.47, 95%CI 1.13–1.92, p 0.004), neutropenia (RR 1.47, 95%CI 1.09–1.99, p 0.012), multiple positive blood cultures (RR 4.23, 95%CI 3.23–5.54, p < 0.001), and CVC (RR 1.60, 95%CI 1.02–2.53, p 0.043) were independent factors for antibiotic duration. ConclusionsQuickFISH implementation plus AS support leads to greater avoidance of vancomycin therapy and improved resource utilization in cancer patients with CoNS blood cultures.