Goodman et al [128] used similar interventions but added a feedback tool using a black-light monitoring system (ie, use of an invisible, nontoxic marker to delineate areas that are adequately or inadequately cleaned) to reduce the likelihood of isolating either MRSA or VRE from an ICU environment. This study also showed favorable results, and notably, the use of the black-light monitoring system identified specific areas that were typically inadequately disinfected. Results showed that flat, horizontal surfaces (eg, countertops, bedside tray tables, and hamper tops) were adequately cleaned more often than small, vertical surfaces (eg, doorknobs, toilet handles, light switches, and electronics).
Part of the controversy surrounding the impact of environmental cleaning is the difficulty in determining its individual value as part of an overall infection control bundle [129]. A proposed area of demonstrable impact for environmental cleaning are frequently touched sites which are more likely to be contaminated with pathogens. Focusing on these “hot-bed” areas of the care environment may offer a useful adjunct to other infection control measures [129].
Active Surveillance
Active surveillance refers to periodic screening for asymp-tomatic carriers followed by placement of colonized patients in contact isolation. This practice is highly variable across institutions, as the evidence supporting this practice is conflicting and there are concerns about the cost of implementing this approach without solid evidence [70,130,131]. Despite lack of randomized controlled trials to guide this practice for MRSA prevention, many hospitals utilize MRSA surveillance and it is mandated by law in 9 states [132,133].
A prospective, interventional cohort study of universal MRSA screening on admission to surgical wards failed to reduce nosocomial MRSA infections [134]. Most recently, a pragmatic, cluster-randomized ICU trial reported that universal decolonization with chlorhexidine wipes and mupirocin use was more effective than screening and isolation in reducing rates of MRSA clinical isolates [65]. However, concerns regarding the risk of mupirocin resistance have been expressed [135,136]. The only randomized trial that compared active surveillance for MRSA and VRE followed by contact precautions to usual care did not find a benefit to active surveillance.
Huskins et al [137], in a large, cluster-randomized trial of 19 ICUs from different hospitals, determined the utility of using a culture-based active surveillance and contact isolation, compared with usual care (contact isolation for patients colonized with MRSA or VRE) as identified by existing hospital protocols, to reduce the incidence of colonization or infection with MRSA or VRE. In this trial, which spanned 6 months and involved 3488 participants, the authors found no significant difference between the intervention and control ICUs in terms of MRSA and VRE colonization or infection rates.
Conflicting with these findings is an observational study comparing MRSA infection rates before and after institution of a universal screening protocol, which demonstrated a 69.6% (CI, –89.2% to –19.6%]; P = 0.03) reduction in hospital wide MRSA prevalence density with screening [138]. The “MRSA bundle” implemented in 2007 at VA hospitals nationwide, which included universal screening, produced a 62% ( P < 0.001) reduction in MRSA ICU infections; the relative contribution of the various bundle components is uncertain [139,140].