Association of oral vancomycin prophylaxis with Clostridium difficile infection in hematopoietic stem cell transplant recipients: A systematic review and meta-analysis.

BACKGROUND

Clostridium difficile infection (CDI) occurs in up to 30% of hematopoietic stem cell transplant (HSCT) recipients and remains a significant cause of infectious diarrhea. This meta-analysis evaluated the association of oral vancomycin prophylaxis (OVP) with CDI prevention after HSCT.

METHODS

We conducted a literature search of PubMed, Cochrane, and Google Scholar for articles from inception to July 2025 that compared the safety and efficacy of OVP for CDI in post-HSCT patients. Statistical analysis of the extracted data was conducted using Review Manager 5.4. The odds ratio for dichotomous variables and the mean difference for continuous variables were analyzed along with the corresponding 95% confidence intervals. A random-effects model was applied when heterogeneity was high (I2 ≥ 50%), and a fixed-effect model was applied when heterogeneity was low (I2 ≤ 50%).

RESULTS

This meta-analysis included 5 studies comprising 957 patients, with 490 (51.2%) receiving OVP and 467 (48.8%) not receiving OVP (no OVP). OVP was significantly associated with a reduced incidence of CDI during hospitalization (P < .00001). Although a lower overall incidence of CDI (hospitalization plus 180-day follow-up) was observed in the OVP group, the result was not statistically significant (P = .06). A leave-one-out analysis was performed to establish a significant association (P = .04). In the OVP group, higher rates of grade 2 to 4 acute graft-versus-host disease (P = .13) and lower rates of bloodstream infections (P = .74), 1-year event-free survival (P = .44), and longer hospital stays (P = .36) were observed, although none reached statistical significance.

CONCLUSION

We conclude that oral vancomycin might be associated with a lower incidence of CDI during hospitalization in post-HSCT recipients and can be considered for CDI prophylaxis. No statistically significant adverse outcomes were observed in the OVP group compared with placebo. However, given the observational nature of these studies, these findings should be considered preliminary. Large-scale randomized controlled trials are needed to confirm the true efficacy and safety profile of OVP in post-HSCT recipients.