Evaluation of Vancomycin-Resistant Enterococci (VRE)–Associated Morbidity Following Relaxation of VRE Screening and Isolation Precautions in a Tertiary Care Hospital

Abstract

OBJECTIVE: To determine whether relaxing vancomycin-resistant enterococci (VRE) precautions results in an increase in the incidence of invasive VRE infections over time. DESIGN: Retrospective analysis of a microbiology database before and after relaxation of VRE screening and isolation precautions. SETTING: Urban tertiary care teaching hospital in Montreal, Canada. PARTICIPANTS: All hospitalized and emergency room patients over a 13-year period from January 1, 2000, to March 31, 2013. METHODS: We assessed the results of all microbiology cultures for the presence of VRE as well as the results of all polymerase chain reaction assays for vanA and vanB during the study period. Applying criteria for 4 clinical situations (bacteremia, definite infection, possible infection, and colonization with VRE), we analyzed the effects of relaxed VRE screening and isolation precautions on the incidence of each of these outcomes over the time preceding and following this change. RESULTS: When VRE screening and isolation precautions were relaxed, a marked rise in VRE colonization was observed, with a lesser but definite rise in the 3 other outcomes. Despite this initial rise in all measures, all incidences other than colonization plateaued during the 34 months of follow-up. CONCLUSIONS: Relaxation of VRE screening and isolation precautions was associated with an immediate increase in colonization and infection incidence. Despite increasing colonization, infection outcomes remained infrequent and stable, suggesting a finite number of susceptible hosts at risk. Relaxation of VRE protocols may not lead to increasing infection incidence in a hospital setting, advocating that cost effectiveness exercises, with targeted screening and isolation precautions, are crucial.