149. Short vs. Long Course of Antibiotics for Uncomplicated Gram-Negative Bacteremia

Background Bloodstream infections (BSI) continue to be a major cause of morbidity and mortality in the United States; thus, the correct choice of antibiotics for an appropriate duration is imperative. However, there are limited recommendations on adequate duration of treatment of bacteremia caused by Gram-negative organisms. Therefore, treating an infection for an adequate duration to prevent complications while preventing adverse effects from unnecessary antibiotic exposure remains a balancing act. This study aims to compare clinical outcomes between patients treated with a short (7–10 days) vs. long (11–20 days) course of antibiotics for uncomplicated gram-negative bacteremia. Methods This single-center retrospective cohort study evaluated adult patients admitted between January 2007 to October 2018 with a blood culture positive for gram-negative bacteria. Data came from the University of Kentucky Microbiological Laboratory and Center for Clinical and Translational Science (CCTS) Data Bank. Patients included must have received appropriate antibiotics for at least 7 days. Appropriate antibiotics were defined as those to which the organism is susceptible with day one of therapy as the first day of appropriate antibiotic therapy. Patients were excluded if they were treated with aminoglycoside monotherapy, had polymicrobial bacteremia, or if treated for longer than 20 days of therapy. Results A total of 466 patients were identified (208 in the short-course group and 258 in the long course group). Gender and ethnicity were similar across both groups. The patients in the long course group had more ICU admissions compared with the short-course group (52.7% vs. 43.3%, P = 0.0426), tended to be older (57 ± 16.7 vs. 53 ± 15.9 years, P = 0.0119), had a higher Charlson Comorbidity Index (5.7 ± 3.6 vs. 4.6 ± 3.6, P = 0.0009) and remained admitted to the hospital longer (23.2 ± 25.6 vs. 15.8 ± 17.5 days, P = 0.0002). However, patients treated with a long course had no difference in 30-day mortality compared with the short-course group (3.9% vs. 3.4%, P = 0.7701). Conclusion Patients with an uncomplicated gram-negative BSI treated with a short course (7–10 days) of antibiotics do not appear to have a significant difference in 30-day mortality compared with those patients treated with a long course (11–20 days). Disclosures All authors: No reported disclosures.