REDUCING TRANSMISSION—MRSA AND VRE PREVENTION STRATEGIES
Evidence-based guidelines developed by the Centers for Disease Control (CDC) Hospital Infection Control Practices Advisory Committee (HICPAC) for prevention of MRSA and VRE are available [68]. Several recently conducted well-designed clinical trials also provide additional insight that may be particularly helpful in the ICU setting [69]. A summary of the MRSA prevention guidelines issued by the CDC and included in its “MRSA toolkit” is provided in Table 3 . A similar guideline on prevention of VRE [70], published more than a decade ago, has similar elements. Table 3 shows a side-by-side comparison of these elements. Unfortunately, despite these guidelines and extensive research regarding prevention and control, considerable controversy exists as to the most effective approaches. As such, these recommendations should be tailored to meet the needs of the specific ICU setting.
Antimicrobial Stewardship
Antibiotic use is a major driver of antibiotic resistance. A meta-analysis by de Bruin and Riley [71] studied the effect of vancomycin usage on VRE colonization and infection. A total of 12 articles describing 13 studies were included; none were randomized controlled trials. All studies were quasi-experimental and lacked control groups. Among all studies, less than half (46%) implemented vancomycin reduction measures as the sole type of intervention [72–76]. The remaining studies implemented other infection control modalities and or restricted the use of other antimicrobials [77–83]. Although all studies that implemented vancomycin restriction alone as a single strategy showed a decline in vancomycin usage, only 2 of these [74,75] showed a relative risk reduction in VRE acquisition post-intervention. Also, studies that restricted vancomycin alone revealed a trend towards lower efficacy in reducing VRE colonization and infection (33%) when compared with those that used additional measures (71%). While judicious antibiotic use should always be practiced, the evidence for vancomycin restriction as a sole intervention to control VRE is scant. It may be that other antibiotics are as big or bigger drivers of resistance in enterococci than vancomycin. For example, a growing body of literature supports antibiotic restriction, especially fluoroquinolones, for reducing MRSA. In several time-series quasi-experimental studies, restriction of fluorquinolones was associated with reduced trends in MRSA infections in the acute care setting, and consideration should be given to monitor and optimize fluoroquinolone use in the ICU setting [84,85].
Antimicrobial stewardship programs are fundamental to optimizing antibiotic use in the ICU and the authors strongly recommend that all ICUs should have such a program in place.
Educational Interventions
Infection control and multidrug-resistant organism (MDRO)–specific education programs for health care workers is a core principle of the CDC’s prevention guidelines. The HICPAC VRE guideline also explicitly states “continuing education programs for hospital staff (including attending and consulting physicians, medical residents, and students; pharmacy, nursing, and laboratory personnel; and other direct patient-care providers) should include information concerning the epidemiology of VRE and the potential impact of this pathogen on the cost and outcome of patient care [70].” A systematic review published in 2008 [86] that included 26 studies showed that such interventions to prevent HCAIs are usually successful; in this review, 20 of 26 studies showed a statistically significant decrease in infection rates, with risk ratios ranging from 0 to 1.6. Education was usually part of a broader array of infection control interventions. While clearly essential, education alone is unlikely to have a sustained impact on reducing MRSA and VRE infections.