Comparison of intravenous vs intravenous with step-down to oral antibiotic treatment course for Streptococcus and Enterococcus bloodstream infections.

Objective: To compare clinical failure of intravenous vs intravenous with oral step-down antibiotic treatment for Streptococcus and Enterococcus bloodstream infection.

Design and setting: Multicenter, retrospective, cohort study at one academic medical center and eight community hospitals.

Patients: Hospitalized adult patients with blood cultures positive for Streptococcus or Enterococcus were included. Patients were excluded if they had complicated infection, had polymicrobial bacteremia, received less than 5 days of therapy, or died before completing therapy.

Methods: Patients who completed intravenous therapy were compared with patients who transitioned to oral therapy after 3 to 7 days. The primary endpoint was clinical failure, defined as 90-day all-cause mortality or recurrent bacteremia. The primary analysis excluded patients with unknown outcomes, and the sensitivity analysis treated them as failures.

Results: 429 patients were included (intravenous group: n = 225; oral step-down group; n = 204). The intravenous group had more comorbidities and vasopressor use. The intravenous group had a higher risk of clinical failure in the primary analysis (17.5% vs. 8.8%; adjusted OR 2.14 [95% CI, 1.09-4.2]; p = 0.03) while the sensitivity analysis found no difference in clinical failure (adjusted OR 1.1 [95% CI, 0.69-1.74], p = 0.69). The oral step-down group had a mean length of stay of 9.2 days shorter than the intravenous group ([95% CI, 7.5-11.0]; p<0.001).

Conclusion: Oral step-down therapy was not associated with an increased risk of clinical failure compared to a full course of intravenous therapy for uncomplicated Streptococcus and Enterococcus bloodstream infections. Patients with more comorbidities or who required vasopressors were less likely to be switched to oral therapy.