Under the Microscope with Bill Rutala: Microbial Burden on Environmental Surfaces

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

Categories: Clinical Pathogens/Alerts & Surface Disinfection October 10, 2021
Hospital Room Patient

Microbial burden on environmental surfaces in patient rooms before daily cleaning-Analysis of multiple confounding variables, authored by Boyce JM, Havill NL, Guercia KA, and Moore BA1 addresses the factors that contribute to an assessment of the microbial burden on environmental surfaces as well as determines the microbial burden on high-touch surfaces before cleaning/disinfection.

The study found that the level of microbial contamination on surfaces varies considerably. About 70% of the surfaces had ≤ 60 aerobic colony counts (ACC)/Rodac (mean 55.6 ACC/Rodac) but some samples were ≥200 ACC/Rodac.  Mean ACCs differed significantly by type of surface, with the highest mean ACCs occurring on surfaces near patients and in bathrooms.  Overall, about 30% of surfaces had ≥ 2.5 CFU/cm2 and would be classified as “dirty” before daily cleaning/disinfection. Using this criterion, the “dirtiest” surfaces were toilet seats (58.6%), bedside rails (52.1%), and bathroom grab bars (43.6%). Mean total ACCs per room did not differ significantly between quaternary ammonium compound (per melt-blown polypropylene wipe) use and improved hydrogen peroxide (per ready-to-use wipe). The mean ACCs differed significantly by site, type of ward, isolation room status, and study period. Surfaces with high ACCs were not necessarily contaminated with pathogens because overall ACCs do not correlate well with the level of pathogens present.

The key takeaways from this study are the level of microbial contamination on surfaces before cleaning/disinfection is generally low (mean 55.6 ACC/Rodac but there is high variance), mean total ACCs per room did not differ significantly between quaternary ammonium compounds, and improved hydrogen peroxide, and microbial burden on environmental surfaces is affected by multiple factors.

Boyce JM, Havill NL, Guercia KA, Moore BA. Microbial burden on environmental surfaces in patient rooms before daily cleaning-Analysis of multiple confounding variables. Infect Control Hosp Epidemiol 2021 Aug 16;1-5. doi: 10.1017/ice.2021.349.

Author

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).

Profile

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).

More about Dr. William A. Rutala, PhD, MPH, CIC Less about Dr. William A. Rutala, PhD, MPH, CIC