Clinical impact of implementation of rapid diagnostic testing of blood cultures with Staphylococcus aureus on patient outcomes

Rapid diagnostic testing in microbiology labs shortens the time to identification of bacteria in blood cultures. Cepheid® GeneXpert® MRSA/SA PCR can be used to distinguish MRSA and MSSA from non-Staphylococcus aureus organisms in blood cultures. This study aims to determine if implementation of MRSA/SA PCR for blood culture pathogen identification, plus daily antimicrobial stewardship intervention, can reduce time to appropriate therapy, vancomycin duration, 30 day mortality, and 90 day recurrence in veterans. A total of 113 patients in the pre-implementation cohort and 73 patients in the post-implementation cohort were evaluated. Time to appropriate therapy was decreased from 49.8 (pre-implementation) to 20.6 (post-implementation) hours. There was a numerically shorter median duration of vancomycin therapy in the post-implementation group. There was no difference in 30 day mortality or 90 day recurrence between groups. Use of MRSA/SA PCR can improve antimicrobial use when combined with once-daily antimicrobial stewardship review.