Program Schedule

Assessment of the Overall and Multi-drug Resistant Organism (MDRO) Bioburden on Environmental Surfaces in Healthcare Facilities

Session: Poster Abstract Session: Cleaning and Disinfection in Healthcare Settings
Saturday, October 11, 2014
Room: The Pennsylvania Convention Center: IDExpo Hall BC
  • 14_CS_251810_HEALTHCARE POSTER - AS ID.pdf (351.2 kB)
  • Background: There is increasing need to understand the role of high-touch environmental surfaces in transmission of MDROs. Despite the likelihood that bacteria are unevenly spread over large surface areas and transmission risk is proportionate to bioburden, previous studies sampled small areas (<100 cm2) qualitatively. Sampling large surface areas (>1000 cm2) quantitatively, we sought to establish overall and MDRO bioburden levels on high-touch surfaces in various healthcare settings after routine (RC) or terminal cleaning (TC).

    Methods: From 11 inpatient healthcare facilities in 4 states, surface samples were collected from high-touch sites in MDRO isolation rooms after RC or TC using a standard sampling protocol.  Two composite samples were collected from each room and a third composite was collected from C. difficile isolation rooms only.  Composite 1 included the TV remote, telephone, call button and bed rails.  Composite 2 included the room door handle, IV pole and over-bed table. Composite 3 included the bathroom (door handle, flush handle and grab bars) or toileting site (portable commode/bedpan).  Samples were processed, the overall bacteria and MDROs (MRSA, VRE, A. baumannii, K. pneumoniae, and C. difficile) were quantified, and results from RC and TC rooms were compared.

    Results: A total of 360 composite samples were collected from 166 rooms (113 RC and 53 TC).  The mean and range of overall bacteria and MDROs recovered is shown in Table 1. MDROs were recovered from 45% (74/166) of rooms; VRE was the most recovered MDRO (19%, 32/166). Higher bioburden was significantly associated with RC rooms (p<0.0001) and composite 1 (p=0.0003).  A room bioburden level >1,281 CFU/100 cm2 increases the risk of recovering any MDRO from the room (RR=2.02, p<0.0001).

    Table 1.

    Room Type

    Overall Bacteria Mean CFU/100 cm2 (Range)

    MDRO Mean CFU/100 cm2 (Range)


    5,780 (≤1 – 147,000)

    480 (≤1 - 13,000)


    790 (≤1 – 7,800)

    23 (≤1 – 59)

    Conclusion: RC MDRO rooms, specifically surfaces close to the patient (composite 1), are more likely to have higher bioburden which may increase the risk of recovering an MDRO.  In an effort to prevent transmission of MDROs from the environment it is important to assess an unsafe level of bioburden on surfaces and to determine the adequacy of cleaning methods.

    Alicia M. Shams, MPH, Laura J. Rose, MS, Jonathan R. Edwards, MStat, L. Clifford Mcdonald, MD, FACP, FSHEA, Matthew J. Arduino, MS, DrPH and Judith Noble-Wang, PhD, Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, GA


    A. M. Shams, None

    L. J. Rose, None

    J. R. Edwards, None

    L. C. Mcdonald, None

    M. J. Arduino, None

    J. Noble-Wang, None

    Findings in the abstracts are embargoed until 12:01 a.m. EDT, Oct. 8th with the exception of research findings presented at the IDWeek press conferences.

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