Limiting the Spread of Infection in the Health Care Environment

by Mary G. Lankford, Susan Collins, Larry Youngberg, Denise M. Rooney, John R. Warren, Gary A. Noskin

Published by Coalition of Health Environments Research (CHER) and The Center for Health Design, April 2007

ABSTRACT

Background

Contaminated environmental surfaces, equipment, and healthcare workers’ hands have been linked to outbreaks of infection or colonization due to vancomycin-resistant enterococci (VRE) and Pseudomonas aeruginosa (PSAE). In addition, the composition of certain fibers in textiles and surface structures of building materials such as upholstery, walls, and floors may actually enhance survival of bacteria, therefore providing infectious reservoirs.

Objectives

To investigate the ability of various surfaces to harbor VRE and PSAE; determine recovery of organisms on environmental surfaces after cleaning; and evaluate possible healthcare provider transmission.

Methods

Fourteen environmental surfaces used for upholstery, flooring, and wallcoverings were inoculated with VRE and PSAE and assessed for microbial recovery at 24 hours, 72 hours, and 7 days. Following inoculation, surfaces were cleaned according to manufacturers’ recommendations and samples were obtained.To assess surfaces’ potential for transmission, healthy human volunteers touched VRE-inoculated surfaces with the palmar surfaces of their hands and imprinted them onto contact impression plates.

Results

Twenty-four hours following inoculation, all (100%) surfaces had recovery of VRE and 13 (92.9%) of 14 surfaces had persistent growth of PSAE. After cleaning,VRE was recovered from 5 (35.5%) surfaces and PSAE from 4 (28.6%) surfaces. Cleaning methods were the least effective in removing bacteria from painted walls eliminating 3 log10 of VRE and PSAE. After inoculation followed by palmar contact, VRE was recovered from all 14 surfaces touched.

Conclusion

Many bacteria commonly encountered in hospitals are capable of prolonged survival on environmental surfaces and may promote cross-transmission. Product application and complexity of manufacturers’ recommendations for surface disinfection should be considered when selecting materials for healthcare environments.The recovery of organisms on environmental surfaces, as well as the hands of volunteers, emphasizes the importance of compliance with hand hygiene prior to patient contact.