Oral vancomycin prophylaxis against recurrentClostridioides difficileinfection: Efficacy and side effects in two hospitals

Objective: The data regarding the effectiveness of chemical prophylaxis against recurrentC. difficileinfection (CDI) remain conflicting. Design: Retrospective cohort study on the effectiveness of oral vancomycin for prevention of recurrent CDI. Setting: Two academic centers in New York. Methods: Two participating hospitals implemented an automated alert recommending oral vancomycin 125 mg twice daily in patients with CDI history scheduled to receive systemic antimicrobials. Measured outcomes included breakthrough and recurrent CDI rates, defined as CDI during and 1 month after initiation of prophylaxis, respectively. A self-controlled, before-and-after study design was employed to examine the effect of vancomycin prophylaxis on the prevalence of vancomycin-resistantEnterococcusspp (VRE) colonization and infection. Results: We included 264 patients in the analysis. Breakthrough CDI was identified in 17 patients (6.4%; 95% confidence interval [CI], 3.8%-10.1%) and recurrent in 22 patients (8.3%; 95% CI, 5.3%-12.3%). Among the 102 patients with a history of CDI within the 3 months preceding prophylaxis, 4 patients (3.9%; 95% CIs, 1.1%-9.7%) had breakthrough CDI and 9 had recurrent disease (8.8%; 95% CIs, 4.1%-16.1%). In the 3-month period following vancomycin prophylaxis, we detected a statistically significant increase in both the absolute number of VRE (chi(2), 0.003) and the ratio of VRE to VSE isolates (chi(2), 0.003) compared to the combined period of 1.5 months preceding and the 3-4.5 months following prophylaxis. This effect persisted 6 months following prophylaxis. Conclusions: Prophylactic vancomycin is an effective strategy to prevent CDI recurrence, but it increases the risk of VRE colonization. Thus, a careful selection of patients with high benefit-to-risk ratio is needed for the implementation of this preventive policy.