MRSA/VRE 院內傳播阻止 -> different opinions

Can We Prevent Transmission of Drug-Resistant Bacteria in Hospitals?

Two large studies on active screening for drug-resistant bacteria produced strikingly different results.

How to limit the spread of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) in the healthcare environment remains unclear. This issue was recently addressed in two large clinical studies.

In a cluster-randomized trial involving 18 U.S. adult intensive care units (ICUs), Huskins and colleagues (with partial industry support) examined the effect of MRSA and VRE surveillance. In the 10 intervention ICUs, patients known or found to have MRSA or VRE colonization or infection were managed with contact precautions; all other patients received care with universal gloving pending the results of the screening studies. In the eight control ICUs, standard institutional protocols for managing MRSA and VRE were followed. Routinely scheduled surveillance cultures were obtained in all ICUs, but results were reported only for the intervention ICUs.

During the intervention period (March–August 2006), the mean incidence of MRSA and VRE colonization or infection events, adjusted for baseline incidence, was similar between the intervention and control ICUs (40.4 and 35.6 per 1000 patient-days at risk; P=0.35). The use of contact precautions, although marginally better in the intervention ICUs, was not optimal in either ICU group (appropriate glove use, 82% vs. 72% of contacts; appropriate gown use, 77% vs. 59%; hand hygiene after contact, 69% vs. 59%).

Jain and colleagues investigated the effectiveness of a "MRSA bundle" designed to reduce MRSA transmission in U.S. Veterans Affairs (VA) hospitals. This bundle involved surveillance for nasal MRSA colonization for all patients on admission, after transfer from one inpatient unit to another, and at hospital discharge; contact precautions for all patients with MRSA infection or colonization; hand hygiene; and a change in institutional culture to make prevention of MRSA transmission a responsibility for all healthcare workers.

From October 2007 (when the program was fully implemented in VA hospitals nationwide) through June 2010, the monthly rate of MRSA transmission decreased by 17% in ICUs and by 21% in non-ICUs. The monthly incidence of healthcare-associated MRSA infections in ICUs — which did not decrease significantly during the 2 years before bundle implementation — fell by 62%, with reductions noted for bloodstream infections, pneumonias, urinary tract infections, and skin and soft-tissue infections. A subset of hospitals reported on the incidence of healthcare-associated Clostridium difficile and VRE infections: During the study period, the rate of C. difficile infections did not change significantly in ICUs but decreased by 57% in non-ICUs; the rate of VRE infections fell by 100% in ICUs and by 70% in non-ICUs.

Comment: Huskins and colleagues' results may have been affected by slow identification of colonized patients, as well as by poor adherence to recommended procedures (even with observers in the ICUs). Such lapses in adherence are consistent with the observations of many physicians and infection-control practitioners. Nonetheless, the study findings challenge the paradigm of performing surveillance and then instituting gown-and-glove precautions.

Whether the decrease in MRSA transmission in VA hospitals is attributable to the MRSA bundle is also unclear: The reduction is similar to that observed nationally between 2005 and 2008 (JW Infect Dis Aug 25 2010). Moreover, the fact that there was a concurrent comparable reduction in C. difficile and VRE transmission in VA hospitals suggests that the observed decrease in MRSA transmission might be attributable to greater emphasis on general infection-control measures (e.g., improved hand hygiene and strategies to decrease central line bloodstream infections and ventilator-associated pneumonias), rather than to the MRSA bundle. As noted by an editorialist, these studies underscore the importance of evaluating healthcare practices, including surveillance testing, to determine whether they achieve the expected results.

— Richard T. Ellison III, MD

Published in Journal Watch Infectious Diseases April 13, 2011

頭一篇文章挑戰傳統的”detection"->"接觸隔離"的概念，認為沒有用。但被認為是因為surveillance時效太慢了，已經spreading出去了

第二篇倡導MRSA bundle，但真的是bundle有用嗎？hand hygiene　及其它院感措施（CLBSI bundle)比較有用吧……同一時期其它院感菌種在VA hospital也下降了

Citation(s):

Huskins WC et al. Intervention to reduce transmission of resistant bacteria in intensive care. N Engl J Med 2011 Apr 14; 364:1407.

Jain R et al. Veterans Affairs initiative to prevent methicillin-resistant Staphylococcus aureus infections. N Engl J Med 2011 Apr 14; 364:1419.

Platt R. Time for a culture change? N Engl J Med 2011 Apr 14; 364:1464.