2133. Clinical Impact of Implementation of Rapid Diagnostic Testing of Blood Cultures on Patient Outcomes

Background Rapid diagnostic testing (RDT) in microbiology labs shortens the time to identification of bacteria in blood cultures. This study evaluates the impact of implementation of Cepheid® GeneXpert® to detect methicillin-resistant Staphylococcus aureus and S. aureus in Gram-positive blood cultures. Methods Patients with positive blood cultures for Staphylococcus spp. before (November 2015–August 2016) and after (November 2017–8/2018) implementation of a new rapid diagnostic technology were evaluated. RDT results were reviewed once daily by the antimicrobial stewardship team. The primary outcome was time to appropriate antimicrobial therapy. Secondary outcomes included the duration of antimicrobial therapy from time of positive culture, duration of vancomycin therapy, and length of hospital stay (LOS). Results A total of 113 patients were in the pre- and 73 patients were in the post-implementation cohort. Patients treated post-RDT demonstrated significantly shorter median time to appropriate therapy (20.6 hours vs. 49.8 hours, P = 0.03) and numerically shorter median duration of vancomycin therapy (3.0 days vs. 1.0 days, P = 0.32). These numerical differences were present despite the post-RDT cohort having significantly more MSSA and MRSA infections. Differences in duration of antimicrobial therapy were not statistically significant. Patients treated pre-RDT demonstrated a shorter median LOS than those treated post-implementation (7.0 days vs. 8.5 days, P = 0.03). Conclusion The use of RDT significantly decreased time to appropriate antimicrobial therapy. Patients in the post-RDT cohort had longer LOS, which may due to a higher incidence of S. aureus infections, compared with coagulase-negative Staphylococcus, in this cohort These results are promising for future RDT interventions. Disclosures All authors: No reported disclosures.