Under the Microscope with Bill Rutala: Pathogens on Environmental Sites in Patient Rooms

Author: Dr. William A. Rutala, PhD, MPH, CIC

Categories: General Infection Prevention & Surface Disinfection March 7, 2022

Microbial assessment of healthcare-associated pathogens on various environmental sites in patient rooms after terminal room disinfection authored by Kanamori H, Rutala WA, H, Gergen MF, Sickbert-Bennett EE, Knelson LP, Anderson DJ, Sexton DJ, Weber DJ, and the CDC Prevention Epicenters Program.

Over the past decade, there is excellent evidence in the scientific literature that contaminated environmental surfaces and shared noncritical patient care items play an important role in the transmission of several key healthcare-associated pathogens including methicillin-resistant S. aureus (MRSA), VRE, Acinetobacter, norovirus, and C. difficile. All these pathogens have been demonstrated to persist in the environment for days (in some cases months), frequently contaminate the environmental surfaces in rooms of colonized or infected patients, transiently colonize the hands of healthcare personnel, be transmitted by healthcare personnel, and cause outbreaks in which environmental transmission was deemed to play a role.

Further, admission to a room in which the previous patient had been colonized or infected with MRSA, VRE, Acinetobacter, or C. difficile, has been shown to be a risk factor for the newly admitted patient to develop colonization or infection. Thus, surface disinfection of environmental surfaces and shared medical devices (defined as those that contact intact skin) is one of the important infection prevention strategies to prevent pathogen transmission. In this study, we investigated the microbial burden of aerobic bacteria and epidemiologically important pathogens (EIP) on high-touch hospital room environmental sites after standard or enhanced terminal room disinfection (Quat/UV-C, bleach, or bleach/UV-C) in a large clinical study.

An environmental assessment was performed following terminal room decontamination using Rodac plates to sample 8 of 10 hospital room sites (e.g., bed rail, over bed table, chair, toilet seat). The number of colony-forming units (CFUs) of aerobic bacteria and 4 target EIPs, including multidrug-resistant Acinetobacter (MDRA), methicillin-resistant S. aureus (MRSA), vancomycin-resistant enterococci (VRE), and Clostridioides difficile, was counted. A total of 3675 samples from 736 environmental sites in 92 patient rooms (21 standard and 71 enhanced rooms) at 3 study hospitals were analyzed.

Overall, the frequency of all environmental sites positive for EIP was 11.4% (84/736) in all rooms, 21.4% (36/168) in standard rooms, and 8.5% (48/568) in enhanced disinfection rooms.  Environmental sites in standard rooms were more likely to be contaminated with EIPs than in enhanced disinfection rooms. The mean number of CFUs in EIPs per site was 2.4 in all rooms, 7.6 in standard rooms, and 0.9 in enhanced disinfection rooms.

Our microbial analysis from a large clinical disinfection study demonstrated that enhanced terminal room disinfection, including the use of a UV-C device, reduced the microbial burden of healthcare-associated pathogens, especially MDRA and VRE, on environmental sites better than standard room disinfection.

Disclosure: Dr. Rutala is a consultant for PDI.

Kanamori H, Rutala WA, Gergen MF, Sickbert-Bennett EE, Knelson LP, Anderson DJ, Sexton DJ, Weber DJ and the CDC Prevention Epicenters Program. Microbial assessment of health care-associated pathogens on various environmental sites in patient rooms after terminal room disinfection. Open Forum Infect Dis. 2021. doi:


Dr. William A. Rutala, PhD, MPH, CIC PhD, MPH, CIC
Dr. William Rutala PhD, MPH, CIC Professor in the Division of Infectious Diseases and Director, Statewide Program for Infection Control and Hospital Epidemiology (SPICE).


Dr. Bill Rutala is the Director and co-founder of the Statewide Program for Infection Control and Epidemiology and a Professor for the Division of Infectious Diseases at the University of North Carolina’s School of Medicine.  He was the Director of Hospital Epidemiology, Occupational Health and Safety Program at the University of North Carolina Hospitals for 38 years before retiring in May 2017.

He is a retired Colonel with the U.S. Army Reserve and is certified in infection control.  He has been an advisor to the Centers for Disease Control and Prevention (a former member of the Healthcare Infection Control Practices Advisory Committee [HICPAC], 1999-2003), the Food and Drug Administration (a former member of the General Hospital and Personal Use Devices Panel), the U.S. Environmental Protection Agency (a member of the Scientific Advisory Panel on Antimicrobial Research Strategies for Disinfectants) and the Federal Trade Commission.  Dr. Rutala is a member of various committees on the local, state, national, and international level as well as several professional societies including the American Society for Microbiology, Association for Professionals in Infection Control and Epidemiology (APIC), and the Society of Healthcare Epidemiology of America (SHEA).  He has served or currently serves on the three peer-reviewed journals on infection prevention in the world (i.e., Infection Control and Hospital Epidemiology, American Journal of Infection Control, and The Journal of Hospital Infection)

He has more than 650 publications (peer-review articles, books, book chapters, brief reports) in the fields of disinfection and sterilization (to include several guidelines such as the CDC Guideline for Disinfection and Sterilization in Healthcare Facilities) and epidemiology and prevention of healthcare-associated infections. Dr. Rutala has also been an invited lecturer at over 400 states, national and international conferences (in over 40 states and 40 countries) and has testified twice before the U.S. Congress.  Dr. Rutala earned his Bachelor of Science degree in science from Rutgers University, his master’s degree in microbiology from the University of Tennessee, and both his master’s in public health and a doctorate in microbiology from the University of North Carolina School of Public Health.

His contributions to infection prevention have been acknowledged by professional organizations with the following awards:  Carole M. DeMille Lifetime Achievement Award (APIC, 1999), Lowbury Lecture (Healthcare Infection Society, Scotland, 2002), Hygiene Medal (Rudolf Schulke Foundation, Germany, 2013), Larson Lectureship Award (APIC, 2012), SHEA Lectureship (SHEA, 2012), Barr Distinguished Alumni Award (UNC School of Public Health, 2012), Kelsey Lecture (the United Kingdom, 2001 and 2012), Crawford Award (lifetime achievement, OSAP, 2008), and Favero Lectureship (APIC, 2009). Dr. Rutala has a “named” award in his honor from two international infection prevention professional societies …APIC (William A. Rutala Research Award) and SHEA (William A. Rutala Scholarship).

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