title: Epidemiology of vancomycin-resistant enterococci among patients on an adult stem cell transplant unit: observations from an active surveillance program.
abstract: OBJECTIVE
  To use the findings of an active surveillance program to delineate the unique epidemiology of vancomycin-resistant enterococci (VRE) in a mixed population of transplant and nontransplant patients hospitalized on a single patient care unit.
  
  
  METHODS
  Surveillance survey and case-control analysis.
  
  
  METHODS
  A 19-bed adult bone marrow and stem cell transplant unit at a referral and primary-care center.
  
  
  METHODS
  The study included patients undergoing transplantation, patients who had previously received bone marrow or stem cell transplants, and patients with other malignancies and hematological disorders who were admitted to the study unit.
  
  
  METHODS
  Patients not previously identified as colonized with VRE had perirectal swab specimens collected at admission and once weekly while hospitalized on the unit. The prevalence of VRE colonization at admission and the incidence throughout the hospital stay, genotypes of VRE specimens as determined by pulsed field gel electrophoresis, and risk factors related to colonization were analyzed.
  
  
  RESULTS
  There was no significant difference in the prevalence or incidence of new colonization between nontransplant patients and prior or current transplant recipients, although overall prevalence at admission was significantly higher in the prior transplant group. Preliminary genotypic analysis of VRE isolates from transplant patients suggests that a proportion of cases of newly detected VRE carriage may represent prior colonization not detected at admission, with different risk factors suggestive of a potential epidemiological distinction.
  
  
  CONCLUSIONS
  Examination of epidemiological and microbiological data collected by an active surveillance program provides useful information about the epidemiology of VRE that can be applied to inform rational infection control strategies.
authors.affiliation: Pritzker School of Medicine, University of Chicago, Chicago, Illinois 60637, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Calderwood
authors.forename: Andreas
authors.initials: A
authors.lastname: Mauer
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Tolentino
authors.forename: Ernesto
authors.initials: E
authors.lastname: Flores
authors.forename: Koen
authors.initials: K
authors.lastname: van Besien
authors.forename: Ken
authors.initials: K
authors.lastname: Pursell
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Weber
mesh_terms: D000328:Adult; D053687:Adult Stem Cells / Q000637:transplantation*; D016022:Case-Control Studies; D002641:Chicago / Q000453:epidemiology; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology*; D016983:Enterococcus / Q000235:genetics / Q000502:physiology*; D005260:Female; D005838:Genotype; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology*; D006801:Humans; D015994:Incidence; D008297:Male; D011159:Population Surveillance; D015995:Prevalence; D020713:Vancomycin Resistance