Patients receiving hematopoietic stem cell transplants (HSCT) are at increased risk for Clostridioides difficile infection (CDI). The purpose of this study was to assess the effectiveness of oral vancomycin prophylaxis (OVP) for CDI in HSCT patients.

Single-center, retrospective cohort.

Tertiary care academic medical center in New Jersey.

Patients ≥18 years old during admission for the HSCT were included. Patients who were admitted <72 hours or who had an active CDI prior to HSCT day 0 were excluded.

Medical records of patients admitted between January 2015 and August 2022 to undergo an allogeneic or autologous HSCT were reviewed. The primary end point was the incidence of in-hospital CDI. Secondary end points included the incidence of vancomycin-resistant enterococci (VRE) bloodstream infections, VRE isolated from any clinical culture, gram-negative bloodstream infections, hospital survival, and hospital length of stay. Exploratory end points, including 1-year survival, relapse, and incidence of graft-versus-host disease, were also collected.

A total of 156 HSCT patients were included. There was 1 case of CDI (1 of 81, 1.23%) in the OVP group compared to 8 CDI cases (8 of 75, 10.67%) in the no OVP group (P = .0147). There were no significant (P > .05) between-group differences in incidence of gram-negative bloodstream infections, hospital survival, and length of stay. There were zero clinical cultures positive for VRE.

In-hospital incidence of CDI in HSCT patients was significantly decreased with OVP. Randomized controlled trials are needed in this high-risk population to assess the efficacy and risks of OVP for CDI.

Rapid diagnostic tests (RDTs) are increasingly being implemented as antimicrobial stewardship tools to facilitate antibiotic modification and reduce complications related to their overutilization. We measured the clinical impact of a phenotypic RDT with antimicrobial stewardship (AMS) in the setting of gram-negative bacteremia.

In this single-center retrospective cohort study, we evaluated adult patients with gram-negative bacteremia who received at least 72 hours of an antibiotic.

The primary outcome was the duration of empiric antibiotic therapy for gram-negative bacteremia. Secondary outcomes included time-to-directed therapy, proportion of modifications, hospital length of stay (LOS), and subsequent infection with a multidrug-resistant organism (MDRO) or C. difficile infection (CDI).

The duration of empiric antibiotics decreased in the RDT+AMS group (4 days vs 2 days; P < .01). Time to directed therapy decreased from 75.0 to 27.9 hours (P < .01).

The clinical outcomes of LOS, MDRO, and CDI were reduced. The phenotypic RDT demonstrated an improvement in stewardship measures and clinical outcomes.