1376. Oral Vancomycin as Secondary Prophylaxis Against Clostridioides difficile Infection in Pediatric Patients

BACKGROUND: Secondary oral vancomycin prophylaxis (OVP) has been utilized in adults with a history of Clostridioides difficile infection (CDI) while receiving systemic antibiotics to prevent CDI recurrence. However, this practice is poorly described in pediatric patients. Rates of CDI recurrence in pediatric patients range from 10-40% and is associated with morbidity and mortality. This study assessed the efficacy and safety of secondary OVP in pediatric patients with subsequent antibiotic exposure. METHODS: This retrospective study evaluated pediatric patients ≤18 years with any history of clinical CDI and receiving systemic antibiotics in a subsequent encounter during the time period of 2013-2019. Patients who received OVP 10 mg/kg (up to 125 mg per dose) every 12 hours during concomitant antibiotics were compared to those who did not. The primary outcome was CDI recurrence within 8 weeks following antibiotic exposure. Secondary outcomes included time to recurrence, severity of recurrence, and isolation of vancomycin-resistant enterococci (VRE) from any site. Risk factors for CDI recurrence were assessed using logistic regression. RESULTS: A total of 153 patients were screened for inclusion, of which 32 and 47 patients were assigned to the OVP and no OVP group, respectively. Median age was 8.6 years and the most common comorbidities were malignancy (47%) and immunosuppression (46%). Median time since last CDI to study inclusion was 64.5 days in the OVP group and 90 days in the no OVP group, P=0.320. Compared to the no OVP group, OVP patients had longer hospital stays (5 vs 14 days, P=0.001) and more concomitant antibiotic exposure (8 vs 12.5 days, P=0.001). Median duration of OVP was 12 days. CDI recurrence occurred in 12 patients and was significantly lower in the OVP vs no OVP group (3.1% vs 23.4%; odds ratio, 0.106; 95% confidence interval, 0.013-0.864; P=0.022). VRE was not isolated in any patients. After adjustment in a multivariate analysis, only secondary OVP remained as a protective factor against recurrence (odds ratio, 0.082; 95% confidence interval, 0.009-0.748; P=0.027). CONCLUSION: Secondary OVP effectively reduces the risk of recurrent CDI in pediatric patients with a history of CDI while receiving systemic antibiotics. Future prospective studies should validate these findings. DISCLOSURES: Cristian Merchan, PharMD, BCCCP, abbive (Speaker’s Bureau)