2432. Durability Against Antibiotics After Response to Fecal Microbiota Transplantation in Recurrent Clostridioides difficile Infection.

Background Fecal microbiota transplantation (FMT) cures ~90% of patients with recurrent Clostridioides difficile infection (rCDI). Ongoing or repeated exposure to risk factors, especially antibiotics (a modifiable risk factor but often necessary), may lead to future CDI. However, it is not known if FMT provides durable protection against future CDI despite subsequent antibiotic exposure. We studied the long-term durability of FMT against antibiotic exposure post-FMT. Methods A retrospective cohort study of patients undergoing FMT via colonoscopy for rCDI from Sep 2012 - Jun 2018 was performed. Patients were followed up for 1 year after FMT; data regarding future CDI episodes (watery diarrhea with positive stool test after interim symptom resolution), healthcare exposure, systemic non-CDI antibiotics and acid blocker therapy were collected. Primary outcome was 'durability' of response to FMT (defined as no CDI within 1 year post-FMT). Descriptive statistics, Chi square test, Wilcoxon test and multivariate logistic regression were used as appropriate. Results The study included 460 patients; median age 57 years (range 18–94 years), 65.2% (300) female. Overall 31.6% (144) received antibiotics; median number of courses of antibiotics, 2 (range 1–7). Of those who received antibiotics, the incidence of future CDI was 24.3% (n = 34), compared with 9% (n = 28) of those who did not receive antibiotics (P <.001). Median time to first CDI episode post-FMT was 103 (range 5–338) days. Incremental antibiotic courses did not lead to increased risk of future CDI (comparing 1, 2 or ≥3 courses, p =.68). In patients with antibiotic exposure, age and risk factors were similar in patients with and without future CDI (Table 1). Amongst those without antibiotic exposure, inflammatory bowel disease (IBD) predicted future CDI (p =.02). After controlling for risk factors and comorbidities, antibiotic use (p =.004) and IBD (p =.02) independently increased risk of future CDI. Conclusion The majority of patients with rCDI have a durable response to FMT despite ongoing risk factors. These data suggest that three-fourth of patients who receive antibiotics after FMT do not develop future CDI. IBD and antibiotic exposure independently increase the risk of future CDI. Disclosures All authors: No reported disclosures. [ABSTRACT FROM AUTHOR]