# 657. Short-Course vs. Long-Course Antibiotic Therapy for Uncomplicated Enterococcal Bacteremia

## TL;DR

This study found that short antibiotic treatment (4-10 days) for uncomplicated enterococcal bacteremia is as effective as longer treatment (11-17 days) with fewer hospital days.

## Contribution

Demonstrated non-inferiority of short-course antibiotic therapy for uncomplicated enterococcal bacteremia.

## Key findings

- Short-course therapy had non-inferior 30-day mortality compared to long-course therapy.
- Short-course therapy reduced hospital length of stay and increased antibiotic-free days.
- No significant differences in clinical cure or relapse rates between the two groups.

## Abstract

The optimal duration of treatment for uncomplicated enterococcal bacteremia remains undefined. The 2009 Infectious Diseases Society of America (IDSA) recommends 7 to 14 days of treatment for central-line associated enterococcal bacteremia. We aimed to compare the outcomes of short-course antibiotic therapy (4-10 days) versus long-course therapy (11-17 days) in patients with uncomplicated enterococcal bacteremia.

A retrospective study was conducted on adults treated for uncomplicated enterococcal bacteremia between January 1st, 2021 and December 31st, 2024 across four acute-care hospitals in Miami, Florida. Uncomplicated enterococcal bacteremia was defined as having a monomicrobial positive blood culture with Enterococcus sp., along with clinical stability and microbiological clearance within 72 hours following treatment. Persistent bacteremia, lack of source control, and deep-seated infections were excluded. The primary outcome was 30-day mortality and secondary outcomes included clinical cure, 30-day microbiological relapse, antibiotic-free days, hospital length-of-stay, 90-day Clostridium difficile rate, and 30-day hospital readmission rate. A sample size of 276 patients was needed to achieve 80% power and a non-inferiority margin was set at 10%.

Of the 1,140 patients screened, 276 patients were included: 127 (46%) patients in short-course treatment and 149 (54%) patients in long-course treatment. The primary outcome of 30-day all-cause mortality occurred in 7 patients (5.5%) in the short-course group vs 6 patients (4.0%) in the long-course group ([risk difference, -1.49% [95% confidence interval, –6.50% to 3.53%]). No significant differences were observed in clinical cure, microbiological relapse, hospital readmission, and Clostridium difficile infections. Short-course compared to long-course therapy had reduced hospital length of stay (16 vs. 21 days; p< 0.03) and increased antibiotic-free days (18 vs. 13 days; p< 0.00001); step-down from intravenous to oral therapy occurred at a median of 4 and 5 days, respectively.

Among hospitalized patients with uncomplicated enterococcal bacteremia, antibiotic treatment with short-course therapy was noninferior to treatment with long-course therapy.

All Authors: No reported disclosures