2397. Effects of antimicrobial surgical prophylaxis on rates of Clostridioides difficile infection

BACKGROUND: Studies have demonstrated short courses of antibiotics, including surgical site infection (SSI) prophylaxis, can increase the risk of Clostridioides difficile infection (CDI). The purpose of this study was to evaluate the incidence of CDI associated with antibacterial perioperative prophylaxis. METHODS: In a retrospective analysis of affiliated hospitals from a large healthcare system, aggregate data from 156 acute care facilities across the United States was analyzed for the time period of July 2017 through July 2018. Patients were included if they were 18 years and older, admitted to an inpatient unit, and underwent a surgical procedure requiring antibiotic prophylaxis. Patients were excluded if they received antibiotics more than 24 hours prior to procedure start, received antibiotics more than 72 hours after procedure stop, or had more than one procedure with antibiotic prophylaxis within 30 days. Patients were divided into three groups based on the duration of antibiotic prophylaxis received: preoperative only (Pre-op only), pre-op plus postoperative for 24 hours or less (Short Post-op), and pre-op plus post-op for 25 to 72 hours (Long Post-op). The primary outcome was the incidence of CDI within 30 days of surgical procedure. Study design was approved by the University of Tennessee Institutional Review Board. RESULTS: The final analysis included 230,524 patients: 68,307 Pre-op Only, 123,185 Short Post-op, and 39,032 Long Post-op. Overall, 195 cases of CDI were identified during the study period, for a rate of 0.8 cases per 1000 procedures. The highest incidence occurred in the Long Post-op group (1.3 cases per 1000 procedures). A pairwise comparison demonstrated the incidence of CDI is statistically higher in the Long Post-op group compared with both the Pre-op Only (P = 0.005) and the Short Post-op (P = 0.003) groups. There was no significant difference between the Pre-op Only and the Short Post-op groups<./p> CONCLUSION: Patients who received antibiotics for more than 24 hours post-op had a higher incidence of CDI. No statistically significant difference in CDI between pre-op only and less than 24 hours post-op was found. DISCLOSURES: All authors: No reported disclosures.