Risk factors for acquisition of vancomycin-resistant enterococci among patients on a renal ward during a community hospital outbreak

Background: During an outbreak of vancomycin-resistant enterococcal (VRE) i nfection and colonization at a community hospital in Indianapolis, Indiana, we performed a case-control study of patients on the hospital's renal unit to determine risk factors for acquisition of VRE among this potentially hi gh-risk patient population. Methods: Twenty-four renal patients with VRE colonization/infection (ie, ca se-patients) were compared by univariate and multivariate analyses with 29 renal patients with nosocomially acquired vancomycin-susceptible enterococc al infection and colonization (ie, controls). Results: Age and length of hospitalization were similar between the VRE cas e-patients and the vancomycin-susceptible enterococcal control-patients, bu t case-patients had higher Acute Physiology and Chronic Health Evaluation I I scores and received significantly greater numbers of antimicrobials and s ignificantly more days of antimicrobials during the 60 days preceding the f irst positive enterococcal culture. In an assessment of the appropriateness of vancomycin use, one third of vancomycin orders were found to be inappro priate in both patient groups. Conclusions: Our data show that among renal patients, those who are severel y ill and receive multiple and prolonged courses of antimicrobials are at g reatest risk for acquiring VRE infection or colonization. The Centers for D isease Control and Prevention recommends that hospitals develop a comprehen sive plan to prevent and control infection and colonization of patients wit h VRE. This plan should include prompt identification of affected patients, initiation of isolation precautions to prevent patient-to-patient transmis sion of VRE, and prudent use of antimicrobials, including vancomycin.