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

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

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.

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.

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).

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.