Hidden Toll of CRE Colonization: Tripled Three-Year Mortality Risk and Increased Bloodstream Infection Burden After...

Area of Science:

• Infectious Diseases
• Hematology
• Transplantation Medicine

Background:

• Carbapenem-resistant Enterobacteriaceae (CRE) colonization is a significant risk factor for allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients.
• Limited data exists on the long-term consequences of CRE colonization and the efficacy of decolonization strategies in this vulnerable population.

Purpose of the Study:

• To evaluate the long-term impact of pre-transplant CRE colonization on allo-HSCT outcomes.
• To assess the incidence of CRE bloodstream infections (BSI) and associated mortality in colonized versus non-colonized patients.
• To investigate the effect of CRE colonization on engraftment, graft-versus-host disease (GVHD), and overall survival (OS).

Main Methods:

• A prospective study of 240 allo-HSCT recipients screened for pre-transplant rectal CRE colonization.
• Inverse probability of treatment weighting (IPTW) was used for covariate balancing.
• Kaplan-Meier curves and Cox proportional hazards models analyzed outcomes including CRE BSI, engraftment, GVHD, and 3-year OS.

Main Results:

• CRE BSI occurred primarily in colonized patients (26.6%) with high strain and enzyme concordance (81.0% and 77.8%) between colonizing and infecting isolates.
• Colonized patients experienced delayed engraftment and earlier chronic GVHD onset.
• 3-year OS was significantly lower in colonized patients (58% vs 83%) with a 3.49-fold increased mortality risk.

Conclusions:

• Pre-transplant CRE colonization is a strong predictor of adverse allo-HSCT outcomes, including increased CRE BSI, mortality, delayed engraftment, and accelerated GVHD.
• CRE colonization represents a modifiable risk factor, underscoring the need for routine screening and targeted decolonization protocols.
• Implementing effective decolonization strategies is essential to improve survival rates in allo-HSCT recipients.