Microbiology of infection-related complications after transrectal ultrasound-guided prostate biopsy

Introduction: The objective of this study was to describe the incidence, microbiology, and risk factors related to infectious complications after transrectal prostate biopsies. Methods: This was a single-center, retrospective cohort study of patients undergoing prostate biopsies. Throughout the study period, the institutional standard for antibiotic prophylaxis was cephalexin and ciprofloxacin. Due to the desire to limit fluoroquinolone use, the ciprofloxacin duration of therapy was reduced from 48 to 24 hours in the middle of the study period. The primary outcome was the incidence of infection-related complications, defined as a urinary tract infection or bacteremia within 30 days post-procedure. Results: A total of 1471 transrectal prostate biopsies were included. All patients received antibiotic prophylaxis, with 86.1% (1268/1472) of patients receiving both ciprofloxacin and cephalexin. The incidence of infection-related complications was 1.6% (24/1471). Four patients experienced bacteremia, all of which were due to E. coli and all of these patients had received antibiotic prophylaxis with an active antibiotic. The use of ciprofloxacin was associated with a lower risk of infection-related complications (odds ratio [OR] 0.20, 95% confidence interval [CI] 0.07, 0.55). Bacteriuria within one year prior to the procedure was associated with increased risk of infection-related complications (OR 4.77, 95% CI 1.34, 16.93). Four (0.3%) patients experienced an antibiotic-related adverse event. Conclusions: We observed a low rate of infection-related complications and antibiotic-related adverse events in the setting of antibiotic prophylaxis with ciprofloxacin and cephalexin for 24 hours, without pre-procedure rectal culture screening. Investigation into procedural or host factors may uncover opportunities to further reduce infection-related complications.