Dissemination of Methicillin-Resistant Staphylococcus aureus (MRSA) and Viral Surrogate Markers Outside Patient Rooms

Abstract

Background: Patients with methicillin-resistant Staphylococcus aureus (MRSA) colonization often shed MRSA, resulting in contamination of surfaces in their room. It is not known whether MRSA-colonized patients also frequently contaminate surfaces during medical appointments and other activities outside their room. Methods: We conducted an observational cohort study of MRSA-colonized long-term care facility (LTCF) residents to determine the frequency and mechanisms of contamination of surfaces outside patient rooms. Nares, skin, and clothing of patients in contact precautions for MRSA were cultured for MRSA, and high-touch surfaces in the residents’ room were contaminated with the live virus bacteriophage MS2 and cauliflower mosaic virus DNA. The participants were observed during activities and medical appointments outside their rooms for 3 days, and sites that were contacted were sampled for recovery of MRSA, bacteriophage MS2, and cauliflower mosaic virus DNA. Results: As shown in Fig. 1, bacteriophage MS2 and cauliflower mosaic virus DNA was transferred to 1 or more surfaces outside the resident’s room by 5 of the 7 participants, and MRSA was recovered from surfaces touched by 6 (86%) participants. MRSA was recovered during 16 of 35 episodes (46%) where sampling was performed, and recovery was similar for medical appointments (eg, hemodialysis, physical therapy) and nonmedical activities (eg, using the dining room or activity center). Moreover, MRSA, MS2, and the viral DNA marker were recovered both from sites contacted only by participants’ hands and from sites contacted only by clothing. Bacteriophage MS2 and the viral DNA marker were also recovered from portable equipment and from the nursing station. Conclusions: MRSA-colonized LTCF residents frequently disseminated MRSA and viral surrogate markers to surfaces outside their rooms through contact with contaminated hands and clothing. Efforts to reduce contamination of hands and clothing might reduce the risk for pathogen transmission.Funding: NoneDisclosures: None