131. Duration of Therapy for the Treatment of Gram-Negative Bloodstream Infections

BACKGROUND: While current guidelines suggest a total treatment duration of 7 to 14 days for gram-negative bloodstream infections (GN-BSI), there is mounting evidence to suggest that shorter durations may be sufficient. This study compared the treatment outcomes of patients who received short duration therapy (6–10 days) with those who received long durations (11–15 days). METHODS: This was a retrospective study of adult patients who grew an aerobic gram-negative organism from a blood culture while admitted at Strong Memorial Hospital between May 2016 and May 2018. The primary outcome was a composite of mortality and relapsed GN-BSI with the same organism within 90 days of index culture. Secondary outcomes included clinical resolution at end of therapy (EOT), length of stay (LOS), 30-day readmission rate, Clostridoides difficile infection (CDI), development of recurrent GN-BSI resistant to prior antibiotic therapy, and development of multi-drug-resistant (MDR) GN-BSI within 90 days. Appropriate therapy was defined as an antibiotic with confirmed in vitro susceptibility that was either parenteral or a highly bioavailable oral antibiotic (fluoroquinolones or sulfamethoxazole–trimethoprim). RESULTS: Of 600 patients screened, 116 were included in the long duration group and 34 patients in the short-duration group. The majority of patients had a urinary source of infection (59.3%). The primary composite outcome occurred in 11.8% of the short duration group compared with 10.3% in the long (P > 0.999). There was no difference in clinical resolution at EOT, LOS, or rates of CDI, MDR GN-BSI, recurrent GN-BSI resistant to prior therapy, or 30-day readmission. Patients in the long duration group were discharged with longer appropriate outpatient courses (8 days vs. 0.5 days, P < 0.001), which remained significant when including lower bioavailability agents (e.g., oral β lactams) (8 days vs. 5 days, P < 0.001). CONCLUSION: There was no difference in clinical outcomes between the long and short duration therapy for treatment of GN-BSI. This study may support shorter treatment durations for uncomplicated GN-BSI, but should be interpreted cautiously given the smaller sample size. DISCLOSURES: All authors: No reported disclosures.