Infection Control Measures
Major infection control interventions include hand hygiene, the use of personal protective equipment (PPE), and cohorting. These measures can be grouped into “horizontal” (or global) vs. “vertical” (or targeted) strategies. Although not mutually exclusive, horizontal approaches are designed to have an impact on multiple pathogens (pathogen nonspecific), whereas vertical approaches are designed to reduce the impact of specific pathogens (such as VRE). For the purposes of this review, we will discuss both strategies for containment of MRSA and VRE. Horizontal strategies include hand hygiene, universal gloving and/or gowning, environmental cleaning, and daily bathing with chlorhexidine. Vertical strategies include screening for either MRSA or VRE followed by placement in contact precautions and decolonization with mupirocin.
Hand Hygiene
Hand washing is fundamental to reducing transmission of MDROs in health care institutions; however, optimal compliance is hard to achieve and sustain. Barriers to adherence may include unavailability of sinks or hand hygiene materials (eg, alcohol-based gels, gloves) time constraints, forgetfulness, or lack of knowledge [87–95]. Several monitoring strategies have been evaluated to increase compliance with hand hygiene. Most involve direct observation followed by performance assessment and feedback.
Trials examining the impact of improvements in hand hygiene compliance on HAIs in the ICU setting have largely found benefit, although not all studies showed a decline in HAI. In a prospective crossover trial, Rupp et al [96] found dramatic improvements in compliance with hand gel availability, but this did not translate to decreased nosocomial MRSA infections. Venkatesh et al [97] carried out a before-and-after interventional prospective study in a hematology unit in a tertiary level hospital to evaluate the use of an electronic method of surveillance to determine compliance with hand hygiene. The authors also used rates of horizontal transmission of VRE as a secondary end-point. Results of the study showed that hand hygiene compliance improved from 36.3% at baseline to 70.1%. This represented an OR of 4.1 (95% confidence interval, 3.7–4.5), which the authors attributed to the use of automated alerts. VRE transmission rates before and during intervention were not statistically different, but the rates of infection were lower at 1.0 per month in comparison with 4.7 infections per month in the preceding 6 months ( P = 0.096).
While improved hand hygiene may result in significant reductions in HAIs [40], research indicates hand hygiene alone influences about 40% of infections in the ICU setting [98]. As such, hand hygiene should be viewed as a necessary component of a comprehensive infection control program [99]. Despite the success of hand hygiene in reducing HAIs in the ICU, effective strategies to improve compliance remain elusive even under study conditions and further research is needed in this area [100].
Personal Protective Equipment
Tenorio et al [101] conducted a study to assess the effectiveness of gloving in the prevention of hand carriage of VRE by health care workers. The study showed that among 50 health care workers who had contact with patients colonized with VRE, 6 carried a similar patient strain even prior to known contact, and 17 of 44 (69%) had a patient-related VRE strain on their gloves after contact. This suggests a relatively high rate of colonization after usual patient-care contact. Factors associated with acquisition of VRE on gloves included duration of contact, contact with a patient’s body fluids, presence of diarrhea in a patient, mean VRE colony counts on a patient’s skin, and number of body sites colonized with VRE. Although gloves reduced the risk of VRE acquisition of VRE by 71% (ie, 12/17 did not have VRE on their hands after de-gloving) the protection afforded by gloves was incomplete. As such, hand hygiene after glove removal is recommended.