Understanding and Preventing Transmission of Healthcare-Associated Pathogens Due to the Contaminated Hospital Environment

Abstract

Affiliation: 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. Received February 5, 2013; accepted February 10, 2013; electronically published April 9, 2013. 2013 by The Society for Healthcare Epidemiology of America. All rights reserved. 0899-823X/2013/3405-0001$15.00. DOI: 10.1086/670223 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: patients’ endogenous flora, 40%–60%; cross infection via the hands of personnel, 20%–40%; antibiotic-driven changes in flora, 20%–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 (Table 1). 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 multidrugresistant 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. Although pathogen transfer from a colonized or infected patient to a susceptible patient most commonly occurs via the hands of HCP, contaminated hospital surfaces and medical equipment (and, less commonly, water and air) can be directly or indirectly involved in the transmission pathways. These transmission pathways and methods to interrupt transmission have been diagramed. HCP have frequent contact with environmental surfaces in patients’ rooms, providing ample opportunity for contamination of gloves and/or hands. Importantly, hand contamination with MRSA has been demonstrated to occur with equal frequency when HCP have direct contact with a colonized or infected patient or through touching only contaminated surfaces. The most important risk factor for HCP hand and glove contamination with multidrug-resistant pathogens has been demonstrated to be positive environmental cultures. To decrease the frequency and level of contamination of environmental surfaces and medical equipment in hospital rooms, routine and terminal disinfection with a germicide has been recommended. Unfortunately, routine and terminal cleaning of room surfaces by environmental services personnel and medical equipment by nursing staff is frequently inadequate. Multiple studies have demonstrated that less than 50% of hospital room surfaces are adequately cleaned and disinfected when chemical germicides are used. Similarly, inadequate cleaning of portable medical equipment by nursing staff has also been demonstrated. The implementation of enhanced education, checklists, and methods to measure the effectiveness of room cleaning (eg, use of fluorescent dye) with immediate feedback to environmental services personnel has been found to improve cleaning and lead to a reduction in healthcare-associated infections. No-touch methods (eg, ultraviolet C [UV-C] light and hydrogen peroxide systems) have been developed to improve terminal room disinfection. UV-C light has been demonstrated to decrease the level of C. difficile spores on contaminated surfaces in patient rooms, while hydrogen peroxide systems used in rooms of patients colonized or infected with a multidrug-resistant organism has been shown to decrease the risk of a subsequent patient admitted to the room developing infection or colonization with any multidrug-resistant organism. This special issue of Infection Control and Hospital Epidemiology is focused on the epidemiology and prevention of healthcare-associated infections associated with the hospital environment and includes 21 papers. Although space precludes describing each individual paper here, this issue details