2189. Case-Control Study of VRE Acquisition in a Tertiary Care Hospital: Testing the Roles of Antibiotic use, Proton Pump Inhibitor Use and Colonization Pressure
Session: Poster Abstract Session: HAI: MRSA, MSSA, and Other Gram Positives
Saturday, October 7, 2017
Room: Poster Hall CD
  • RishiChanderrajIDweekposter.pdf (455.6 kB)
  • Background: Vancomycin-resistant Enterococcus (VRE) is a leading cause of healthcare associated infections. VRE can asymptomatically colonize the gastrointestinal tract and colonization is a risk factor for subsequent sterile site infection. Active surveillance for colonization using rectal screening and contact precautions of colonized patients has been pursued by multiple institutions. In this setting, risk factors for converting from swab negative to swab positive have not been assessed.

    Methods: We performed a retrospective matched case control study from June 2013 through December 2016 in a single institution. Patients admitted to eight units were routinely screened on admission and weekly thereafter. Cases had a negative swab followed by positive swab more than 3 days after admission. Controls were matched to time from admission to second swab (+/- 5%), unit on which the second swab was performed, and date of admission (+/-365 days). Co-morbidity data, culture data, and antibiotic and proton pump inhibitor (PPI) days on therapy (DOT) were abstracted from the electronic medical record and verified by manual checking 5% of the cohort. A comorbidity risk factor model was generated using conditional logistic regression and backward stepwise removal by AIC criterion to identify comorbidities significantly associated with conversion. With the best fit comorbidity model, colonization pressure, antibiotic use and PPI use were tested.

    Results: We identified 551 cases with matched controls. The comorbidities conferring significantly increased odds ratio (OR) of converting from swab negative to swab positive include age (OR 1.01 per year, p = 0.035), time to index swab (OR 1.5, p = 0.026), neutropenia (OR 1.62, p = 0.014) and renal failure (OR 1.8, p = 0.013). Having one or more DOT of any systemic antibiotic was the largest effect on conversion to VRE positivity (OR 5.6, p < 0.001), but total antibiotic DOT was not significant. Each PPI DOT conferred an OR of 1.06 (p < 0.001). Colonization pressures from patients identified to be carriers and placed in contact precautions did not confer and increased risk.

    Conclusion: : Decreasing PPI use and preventing the initiation of antibiotic when possible should be considered to decrease VRE transmission in the hospital.

    Rishi Chanderraj, MD1, Twisha Patel, PharmD2, Clare Kinnear, PhD MIPH1, Andrew Read, DPhil3, Laraine L. Washer, MD4,5, Keith S. Kaye, MD, MPH6 and Robert Woods, MD PhD1, (1)University of Michigan Health System, Ann Arbor, MI, (2)Michigan Medicine, Ann Arbor, MI, (3)Pennsylvania State University, University Park, PA, (4)Division of Infectious Diseases, University of Michigan Medical School, Ann Arbor, MI, (5)Infection Prevention and Epidemiology, Michigan Medicine, Ann Arbor, MI, (6)University of Michigan Medical School, Ann Arbor, MI


    R. Chanderraj, None

    T. Patel, Merck: Grant Investigator , Research grant

    C. Kinnear, None

    A. Read, None

    L. L. Washer, None

    K. S. Kaye, Xellia: Consultant , Consulting fee
    Merck: Consultant and Grant Investigator , Consulting fee and Research support
    The Medicines Company: Consultant and Grant Investigator , Consulting fee and Research support

    R. Woods, None

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