1137. The Association of Antibiotic Exposure and VRE Re-colonization at the NIH Clinical Center: A Cohort Study
Session: Poster Abstract Session: MRSA/VRE Epidemiology
Friday, October 9, 2015
Room: Poster Hall
  • ID Week 2015_Heather Hughes.pdf (2.1 MB)
  • Background: Vancomycin-resistant Enterococcus faecium (VRE) commonly cause healthcare-associated infections, especially among immunosuppressed patients. In the NIH Clinical Center, VRE colonized/infected patients are placed in contact isolation. Discontinuation of isolation requires evidence that fecal carriage of VRE is consistently undetectable (“decolonization”). Criteria for decolonization in our hospital include negative VRE PCRs or cultures on 3 consecutive perirectal swabs 1 week apart, starting ≥ 4 weeks after the last positive swab. Even after decolonization, some patients later regrow VRE and are deemed “re-colonized.” Whether re-colonization represents recrudescence or new acquisition of VRE is not clear; antibiotics could disrupt intestinal flora and create a favorable environment for VRE regrowth. The objective of this study is to determine whether inpatient antibiotic receipt is associated with VRE re-colonization among decolonized patients. 

    Methods: We performed a retrospective cohort study of patients with VRE colonization/infection who met criteria for decolonization between 2007-2015 at the NIH Clinical Center. Antibiotic exposure was measured as the percentage of antibiotic days per number of VRE decolonized days and analyzed as a binary variable greater than or less than the median. The relationship of antibiotic exposure and time to VRE re-colonization was assessed via survival analysis using Cox proportional hazards regression.

    Results: 350 inpatients were identified as VRE colonized/infected; 72 (21%) met decolonization criteria. 21 (29%) of these 72 patients subsequently became re-colonized with VRE, whereas 51 (71%) remained decolonized. The hazard of VRE re-colonization was 6.7 (95% CI 2.7, 16.3) and 4.6 (95% CI 2.1, 9.9) times higher in patients with a percentage of antibiotic days and anti-anaerobic antibiotic days above the median, respectively, after adjustment for confounding by age, race and gender.

    Conclusion: The proportion of antibiotic and anti-anaerobic antibiotic days to the number of VRE decolonized days was significantly related to VRE re-colonization. This finding warrants more careful antimicrobial stewardship and adjustment of targeted surveillance for reappearance of VRE colonization.

    Heather Y. Hughes, M.D., M.P.H.1, Robin T. Odom, M.S.2, Angela V. Michelin, M.P.H.2, Evan S. Snitkin, Ph.D.3, Ninet Sinaii, Ph.D., M.P.H.4, Aaron Milstone, M.D., M.H.S.5, David K. Henderson, M.D., FIDSA, FSHEA6 and Tara N. Palmore, M.D.2, (1)National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, (2)Hospital Epidemiology Service, National Institutes of Health Clinical Center, Bethesda, MD, (3)Microbiology and Immunology, University of Michigan, Ann Arbor, MI, (4)Biostatistics and Clinical Epidemiology Service, National Institutes of Health Clinical Center, Bethesda, MD, (5)The Johns Hopkins Medical Institution, Baltimore, MD, (6)National Institutes of Health Clinical Center, Bethesda, MD


    H. Y. Hughes, None

    R. T. Odom, None

    A. V. Michelin, None

    E. S. Snitkin, None

    N. Sinaii, None

    A. Milstone, Sage Products LLC: Grant Investigator , Grant recipient

    D. K. Henderson, None

    T. N. Palmore, None

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 7th with the exception of research findings presented at the IDWeek press conferences.