Efficacy of oral vancomycin prophylaxis for prevention of Clostridioides difficile infection: a systematic review and meta-analysis

Background: Prevention of recurrent Clostridioides difficile infection (CDI) is a challenge in clinical practice, particularly in patients who need systemic antimicrobial therapy. We aimed to evaluate the role of oral vancomycin prophylaxis (OVP) in prevention of primary or future CDI in patients on systemic antimicrobial therapy. Methods: A systematic search of MEDLINE, Embase, and Web of Science was performed from 2000 to January 2020. We included case-control or cohort studies that included patients on systemic antimicrobial therapy who did or did not receive oral vancomycin prophylaxis (OVP) and were evaluated for development of CDI. Odds ratio (OR) estimates with 95% confidence intervals (CI) were calculated. Results: Four studies including 1352 patients evaluated OVP for primary CDI prevention, with CDI occurring in 29/402 patients on OVP (7.4%) compared with 10.4% (99/950) without OVP. Meta-analysis revealed no significant decrease in risk of CDI in patients who received OVP (OR, 0.18; 95% CI, 0.03-1.03; p = 0.06). There was significant heterogeneity with I-2 = 76%. Ten studies including 9258 patients evaluated OVP for secondary CDI prevention. Future CDI occurred in 91/713 patients on OVP (13.3%) compared with 21.9% (1875/8545) who did not receive OVP. Meta-analysis revealed a statistically significant decreased risk of future CDI (OR, 0.34; 95% CI, 0.20-0.59; p < 0.00001). Significant heterogeneity was seen with I-2 = 59%. Discussion: Based on observational data, OVP appears to decrease the risk of future CDI in patients with prior CDI who require systemic antimicrobial therapy. However, OVP was not effective for primary prevention of CDI.