Usha Stiefel MD, of the Cleveland Veterans Affairs Medical Center in Cleveland, Ohio, and colleagues, have demonstrated in a new study in Infection Control and Hospital Epidemiology that hand contamination was likely to be equal after contact with commonly examined patient skin sites and commonly touched environmental surfaces in patient rooms, and that their findings suggest that contaminated surfaces may be an important source of methicillin-resistant Staphylococcus aureus (MRSA) transmission.
As the researchers note, "The relative importance of environmental surfaces compared with patients’ skin as a source for contamination of the hands of healthcare workers is unclear. Because some studies suggest that acquisition of S. aureus on hands is common after contact with contaminated surfaces, we hypothesized that the frequency of MRSA acquisition and the quantity of MRSA acquired on hands is similar after contact with skin sites and environmental surfaces in the rooms of MRSA carriers."
In their two-month study at a 285-bed Veterans Affairs hospital that conducts surveillance for anterior nares carriage of MRSA for all inpatients, the researchers enrolled a sample consisting of 40 patients admitted with MRSA colonization or infection. During the study, sodium hypochlorite (5,000 ppm) was used for disinfection of rooms after discharge of MRSA patients, but "high-touch" surfaces were not cleaned on a daily basis unless they were visibly soiled.
The researchers obtained samples for gloved hand-imprint cultures from patient skin sites such as the abdomen, chest, forearm, and hand, as well as from environmental sites including the bed rail, bedside table, telephone, and call button, to compare the risk of hand contamination after contact with skin compared with the environment,
Stiefel, et al. report that the risk of any gloved-hand contamination after contact with the skin sites and the environmental surfaces was not significantly different (40 percent v ersus 45 percent ). They add that t here was also no significant difference in the mean number of colony-forming units ( CFUs ) per gloved handprint acquired after contact with skin and environmental sites . The most frequent skin and environmental sites associated with hand acquisition were the abdomen or chest and the call button, respectively. Of the skin sites, patients’ abdomen had the highest number of colonies acquired on gloved hands. Of the environmental sites, the call button had the highest number of colonies acquired by gloved hands.
The researchers write, "Our findings have several practical implications for control of MRSA. First, our findings provide support for the recommendation that healthcare workers routinely disinfect their hands after contact with inanimate objects in the immediate vicinity of patients. In our facility, healthcare workers’ compliance with hand hygiene is statistically significantly lower after contact with environmental surfaces only compared with that after contact with patients (authors’ unpublished data), suggesting that healthcare workers need education regarding the importance of the environment as a source for hand contamination. Second, because MRSA may survive for long periods on surfaces, our findings reinforce the importance of environmental disinfection after discharge of MRSA patients. Finally, it is possible that daily disinfection of high-touch surfaces in MRSA isolation rooms might reduce the level of contamination and decrease the risk for acquisition on healthcare workers’ hands."
Reference: Stiefel U, Cadnum JL, Eckstein BC, Guerrero DM, Tima MA and Donskey CJ. Contamination of Hands with Methicillin-Resistant Staphylococcus aureus after Contact with Environmental Surfaces and after Contact with the Skin of Colonized Patients. Infection Control and Hospital Epidemiol. Vol. 32, No. 2. February 2011.