Slaughter et al [102] compared the use of personal protective equipment in the acquisition of VRE. During this study, 93 patients in glove-and-gown rooms and 88 patients in glove-only rooms had similar rates of VRE at baseline entry into the ICU and after the intervention. Mean times to colonization among the patients who became colonized were 8.0 days in the glove-and-gown group and 7.1 days in the glove-only group. None of these comparisons were statistically significant and the authors concluded that the universal use of gown and gloves was no better than the use of gloves alone in preventing VRE colonization.
A recent cluster randomized trial compared the effect of universal PPE (ie, gowning and gloving) with usual care for reducing acquisition of MRSA or VRE as a composite outcome [103]. The study did not find that universal gowning and gloving reduced VRE or MRSA acquisition but found a 40% decline in MRSA acquisition in the intervention ICUs compared with baseline rates of MRSA. No major adverse effects of universal gowning and gloving were noted in this study. A thoughtful editorial commenting on this article proposes that several aspects of the study deserve consideration, including the possibility of false-negative screening tests for VRE, which may have partially accounted for the negative primary outcome [69].
Based on these studies, it appears that the use of barrier precautions may be of value more for MRSA than VRE but further studies are needed to examine its impact on other types of pathogens, including new and emerging MDROs. Until further evidence becomes available, routine gowning and gloving may be of value in units with a high prevalence of MRSA.
Environmental Cleaning
Accumulating data suggests that the environment may play a major role in transmission of pathogens. MRSA has the ability to survive for days to weeks on inanimate objects [104–107]. Environmental contamination results in contamination of staff clothing and gloves [107,108] and is highly correlated with colonization strains among inpatients [109]. Although some studies of enhanced cleaning techniques and increased environmental services staff time have demonstrated reductions in MRSA outbreaks [110–112], the results are not universally favorable [113,114] and further studies are needed to examine the impact of environmental cleaning on rates of MRSA colonization or infection.
Several studies have implicated contaminated equipment as vectors for transmission of VRE during outbreaks [115–117], but the direction of fomite transfer from patient to environment has been difficult to ascertain. VRE have been found frequently on a variety of inanimate objects and surfaces in different health care environments [118–123], including gloved or ungloved hands of health care workers [101,124,125]. Hayden et al [126] determined the effect of improved environmental cleaning on VRE acquisition rates. This study was a pre-and-post intervention study carried out in a 21-bed medical intensive care unit (MICU) in a tertiary hospital over several phases. The intervention included the creation of a unique and improved cleaning program, as well as in-services to housekeeper services, education of the MICU staff, and a hand hygiene campaign. The results of the study showed decreased acquisition of VRE from 33.47 cases per 1000 patient days at risk in period 1 to 10.40 cases per 1000 patient-days at risk by period 4 of the study. Increased environmental cleaning was also associated with reduced growth of VRE from environmental cultures. At baseline, weekly contamination rates were 0.15 and 0.1 for samples obtained before and after cleaning, respectively. Culture positivity decreased to 0.07 and 0.04 for before and after cleaning in period 2 and then remained at low levels during the remainder of the study. It is important to note that the method for disinfecting used in this study was the “bucket method” as promoted by Byers [127]. This study provides further support for the importance of an environmental reservoir and of environmental decontamination to prevent endemic cross-transmission of VRE [126].