Vancomycin-resistant enterococcal bloodstream infections on a hematopoietic stem cell transplant unit: are the sick getting sicker?

Abstract

Patients with hematologic malignancies and hematopoietic stem cell transplant (HSCT) recipients are at high risk for bacterial bloodstream infections (BSI) owing to resistant organisms. Data describing the outcomes of vancomycin-resistant enterococcal (VRE) BSI in this patient population are limited. We performed a retrospective cohort study of all cases of VRE BSI that occurred between February 1996 and December 2002 on the Leukemia/HSCT unit at Barnes-Jewish Hospital. There were 68 episodes of VRE BSI in 60 patients with acute (53%) or chronic (8%) leukemia, non-Hodgkin's lymphoma (22%) or other malignant hematologic disorders (17%). A total of 13, 32 and 32% were recipients of autologous, related and matched-unrelated transplants, respectively. Forty-two of allograft recipients had active acute graft-versus-host disease (GVHD) and 32% chronic GVHD. Only 57% were neutropenic, 52% had refractory/relapsed malignancy and 60% had end organ dysfunction with a median APACHE II score of 17. Median survival after VRE BSI was 19 days. Pneumonia, receipt of anti-fungal drugs and low APACHE II score at the time of the VRE BSI remained significant risk factors for death on multivariable analysis. Our analysis suggests that in patients with hematological malignancies or HSCT, VRE may not have the behavior of a virulent pathogen. VRE BSI may simply be a marker of these patients' already existing critical medical condition.