Hand Acquisition of Methicillin-Resistant Staphylococcus aureus After Contact With Environmental Surfaces Versus Skin of Colonized Patients

Background: The skin of patients with methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection and contaminated environmental surfaces are considered important reservoirs for transmission. However, the relative importance of environmental surfaces versus patients’ skin as a source for contamination of healthcare workers’ hands is unknown. Objective: We tested the hypothesis that the frequency and quantity of MRSA acquired on hands is similar after contact with environmental surfaces and patient skin sites in a tertiary-care VA medical center that performs active surveillance for MRSA on all admitted patients.  Methods: Gloved hand imprint cultures of commonly touched environmental surfaces (bed rail, bedside table, telephone, and call button) in the rooms of patients identified as nasal MRSA carriers were obtained.  Similar cultures were obtained from commonly examined skin sites (chest, abdomen, hands, and forearm) of nasal MRSA carriers. The proportions of contamination and the numbers of colonies acquired were compared using Student's T-test and Fisher's exact test, respectively. Results: For 40 MRSA carriers studied, the risk of hand contamination was not significantly different after contact with commonly examined skin sites versus commonly touched environmental surfaces (40% versus 45%, respectively; P = 0.69). The mean numbers of colonies obtained on hands after contact with the skin versus environmental sites were not significantly different (16.5 [range 1-53] versus 13.3 [range 1-50], respectively; P = 0.82). The most frequent skin and environmental sites associated with hand acquisition were the chest and bed rail, respectively. Conclusions: Commonly touched environmental surfaces in MRSA colonized patients’ rooms and commonly examined skin sites are equally important sources for acquisition of MRSA on hands. These results reinforce the importance of environmental disinfection and use of gloves or best performance of hand hygiene when touching environmental surfaces in rooms of MRSA-colonized patients.