Prophylactic Vancomycin in the Primary Prevention of Clostridium difficile in Allogeneic Stem Cell Transplant.

Background: Clostridium difficile (C. difficile) infection is a frequent complication following hematopoietic stem cell transplant, contributing to increased morbidity in this population. Despite current infection prevention strategies, rates among posttransplant patients at some centers remain high. Oral vancomycin is a safe and well-tolerated antibiotic that may be a potential adjunct to prevent C. difficile.

Objectives: To evaluate the effectiveness of oral vancomycin in preventing C. difficile among allogeneic stem cell transplant patients and assess other posttransplant outcomes.

Study design: A retrospective cohort study was conducted comparing the rate of C. difficile following allogeneic transplant in patients who received oral vancomycin versus no prophylaxis during hospitalization. The primary outcome was the development of C. difficile infection within the first 100 days following transplant, defined as a positive stool toxin assay or PCR. Secondary outcomes included hospital length of stay, hospital-acquired infections, overall mortality, graft-versus-host disease (GVHD), and rehospitalization.

Results: Among the 202 patients, one case of C. difficile occurred in the prophylaxis group (1/71, 1.4%) compared to 31 cases in the unexposed group (31/131, 23.6%). Patients who received prophylaxis were significantly less likely to develop C. difficile infection during the study period (OR 0.046, p = 0.003). No differences were observed between groups in hospital-acquired infections, mortality, incidence of acute GVHD, and rehospitalization.

Conclusion: Prophylactic vancomycin was associated with a marked reduction in C. difficile infection in allogeneic transplant patients. Despite no significant impact on other clinical outcomes, there was a significant reduction in symptomatic C. difficile infection. Further prospective studies are warranted.