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Updated: Jun 3, 2026
Microbial Control and Monitoring Strategies for Cleanroom Environments and Cellular Therapies
Published on: March 17, 2023
Environmental cleaning intervention and risk of acquiring multidrug-resistant organisms from prior room occupants
Rupak Datta1, Richard Platt, Deborah S Yokoe
1Division of Infectious Diseases and Health Policy Research Institute, University of California Irvine School of Medicine, 100 Theory, Ste 110, Irvine, CA 92697, USA. rdatta@uci.edu
Background:
Admission to intensive care unit rooms previously occupied by carriers of methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant enteroccoci (VRE) had been found to confer a 40% increased risk of acquisition, presumably through environmental contamination. Subsequently, a cleaning intervention was shown to reduce MRSA and VRE room contamination. We now evaluate the effect of this intervention on the risk of acquiring MRSA and VRE from prior room occupants.
Methods:
We conducted a retrospective cohort study of patients admitted to 10 intensive care units at a 750-bed academic medical center during the enhanced cleaning intervention (from September 1, 2006, through April 30, 2008; n = 9449) vs baseline (from September 1, 2003, through April 30, 2005; n = 8203) periods. The intervention consisted of targeted feedback using a black-light marker, cleaning cloths saturated with disinfectant via bucket immersion, and increased education regarding the importance of repeated bucket immersion during cleaning. Intensive care units included medical, cardiac, burn/trauma, general surgery, cardiac surgery, thoracic surgery, and neurosurgery units. We calculated the number of room stays involving the potential for MRSA and VRE acquisition and then assessed the frequency at which eligible patients were exposed to rooms in which the prior occupants had MRSA-positive or VRE-positive status.
Results:
Acquisition of MRSA and VRE was lowered from 3.0% to 1.5% for MRSA and from 3.0% to 2.2% for VRE (P < .001 for both). Patients in rooms previously occupied by MRSA carriers had an increased risk of acquisition during the baseline (3.9% vs 2.9%, P = .03) but not the intervention (1.5% vs 1.5%, P = .79) period. In contrast, patients in rooms previously occupied by VRE carriers had an increased risk of acquisition during the baseline (4.5% vs 2.8%, P = .001) and intervention (3.5% vs 2.0%, P < .001) periods.
Conclusions:
Enhanced intensive care unit cleaning using the intervention methods may reduce MRSA and VRE transmission. It may also eliminate the risk of MRSA acquisition due to an MRSA-positive prior room occupant.
Insights
An enhanced cleaning intervention significantly reduced methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) acquisition in intensive care units. This intervention also eliminated the increased risk of MRSA acquisition from previous room occupants.
Area of Science:
- Infectious Diseases
- Hospital Epidemiology
- Infection Control
Background:
- Intensive care unit (ICU) rooms previously occupied by patients carrying MRSA or VRE pose a significant risk of acquisition due to environmental contamination.
- A prior cleaning intervention demonstrated a reduction in MRSA and VRE room contamination.
Purpose of the Study:
- To evaluate the effectiveness of an enhanced cleaning intervention in reducing the risk of MRSA and VRE acquisition from prior room occupants in ICUs.
- To assess the impact of the intervention on patient acquisition of these multidrug-resistant organisms.
Main Methods:
- A retrospective cohort study compared ICU patients during an enhanced cleaning intervention period (2006-2008) with a baseline period (2003-2005).
- The intervention involved targeted feedback, specialized cleaning cloths, and increased education on disinfection techniques.
- Data on room occupancy, prior occupant status (MRSA/VRE positive), and patient acquisition were analyzed across 10 ICUs.
Main Results:
- Overall acquisition of MRSA decreased from 3.0% to 1.5%, and VRE from 3.0% to 2.2% (P < .001 for both).
- The increased risk of MRSA acquisition from prior carriers was eliminated during the intervention period (1.5% vs 1.5%, P = .79).
- However, an increased risk of VRE acquisition from prior carriers persisted during the intervention period (3.5% vs 2.0%, P < .001).
Conclusions:
- Enhanced ICU cleaning protocols, including targeted feedback and improved disinfection methods, show promise in reducing MRSA and VRE transmission.
- The intervention appears effective in mitigating the risk of MRSA acquisition associated with previous room occupants.
- Further strategies may be needed to fully address VRE transmission linked to prior room occupants.
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