328. Trends in Multidrug Resistant Bacteria and Clostridium difficile in an Integrated Healthcare Network, 2008-2015
Session: Poster Abstract Session: HAI: Multi Drug Resistant Gram Negatives
Thursday, October 27, 2016
Room: Poster Hall
  • ID Week Poster 2016 328 Print.pdf (2.9 MB)
  • Background:

    Multidrug resistant bacterial (MDRO) and Clostridium difficile infections are threats to patient safety. The objective of our study was to describe the burden of MDROs and Clostridium difficile and to depict changing trends over time in an integrated healthcare network.


    We abstracted electronic data from patients seen at any of Intermountain Healthcare’s 22 hospitals and affiliated clinics between January 1, 2008 and December 31, 2015 who had clinical cultures positive for antibiotic resistant Gram-positive or Gram-negative bacteria and/or a laboratory tests positive for toxigenic C. difficile. MDRO was defined as resistance to ≥3 antibiotic classes, pan-resistance as resistance to all antibiotics tested. Carbapenem resistant Enterobacteriaceae (CRE) was defined according to CDC definitions.  Specimens collected after > 48h (for C. difficile ≥72h) from time of admission were classified as hospital acquired.


    A total of 62,480 cultures collected from 39,158 patients yielded an organism of interest from 4,019,150 total patient encounters. The prevalence of all studied organisms was 155 per 10,000 patient encounters and incidence of 82 per 10,000 patient encounters. Of the 900,000 hospital admissions during the study period, 12,905 (1.4%) were from patients positive for an MDRO and/or C. difficile. Methicillin resistant Staphylococcus aureus, C. difficile and ESBL harboring Gram-negative rods were the most common organisms (Figure A). We observed a 222% increase in the prevalence of C. difficile and a 322% increase in ESBL positive organisms from 2008 to 2015 whereas the prevalence of MRSA decreased by 32% (Figure B). All other organisms occurred at a roughly constant rate over time. MRSA, ESBL E. coli and CRE E.coli were less frequently acquired in the hospital; however, vancomycin resistant E. faecium, MDRO P. aeruginosa and other CRE were more frequently acquired in hospitals (Figure C).


    We describe changing epidemiology of MDROs over the study period. While MRSA continues to be the most common antibiotic resistant bacteria, rates have been declining. In contrast, ESBL and C. difficile rates continue to increase. The rate of acquiring an MDRO in acute care facilities varies by bacterial species. Understanding these trends helps focus limited infection control resources. 

    Bert K. Lopansri, MD1,2, Dominika Swistun, PhD candidate3, Rajesh Mehta, RPh, MS1, Brandon Webb, MD3, Edward Stenehjem, MD, MSc4, Michelle Keane, BS, MBA5, David Pombo, MD6, Kristin Dascomb, MD, PhD7 and John Burke, MD, FIDSA, FSHEA1,2,8, (1)Clinical Epidemiology and Infectious Diseases, Intermountain Medical Center, Murray, UT, (2)Division of Infectious Diseases, University of Utah School of Medicine, Salt Lake City, UT, (3)Intermountain Medical Center and LDS Hospital, Murray, UT, (4)Division of Infectious Diseases, Intermountain Medical Center, Murray, UT, (5)Enterprise Analysis Corporation, Stamford, CT, (6)Cape Code Healthcare, Hyannis, MA, (7)Intermountain Healthcare, Murray, UT, (8)LDS Hospital, Salt Lake City, UT


    B. K. Lopansri, None

    D. Swistun, None

    R. Mehta, None

    B. Webb, None

    E. Stenehjem, None

    M. Keane, None

    D. Pombo, None

    K. Dascomb, None

    J. Burke, None

    Findings in the abstracts are embargoed until 12:01 a.m. CDT, Wednesday Oct. 26th with the exception of research findings presented at the IDWeek press conferences.