More than 20 years ago, Dr Robert Weinstein estimated that the source of pathogens causing a healthcare-associated infection in the intensive care unit was as follows: patientsâ€™ endogenous flora, 40%â€“60%; cross infection via the hands of personnel, 20%â€“40%; antibiotic-driven changes in flora, 20%â€“25%; and other (including contamination of the environment), 20%.
Over the past decade, substantial scientific evidence has accumulated indicating that contamination of environmental surfaces in hospital rooms plays an important role in the transmission of several key healthcare-associated pathogens, including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), Clostridium difficile, Acinetobacter, and norovirus.
All of these pathogens have been demonstrated to persist in the environment for hours to days (and, in some cases, months), to frequently contaminate the surface environment and medical equipment in the rooms of colonized or infected patients, to transiently colonize the hands of healthcare personnel (HCP), to be associated with person-to-person transmission via the hands of HCP, and to cause outbreaks in which environmental transmission was deemed to play a role. Furthermore, hospitalization in a room in which the previous patient had been colonized or infected with MRSA, VRE, C. difficile, multidrug-resistant Acinetobacter, or multidrug-resistant Pseudomonas has been shown to be a risk factor for colonization or infection with the same pathogen for the next patient admitted to the room.
David J. Weber, MD, MPH -1
William A. Rutala, PhD, MPH -1
1. Department of Hospital Epidemiology, University of North Carolina Health Care, Chapel Hill, North Carolina; and Division of Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, North Carolina
Address correspondence to David J. Weber, MD, MPH, 2163 Bioinformatics, CB 7030, Chapel Hill, NC 27599-7030 ([email protected]).