NEJM：普遍去定植可更有效防止ICU内感染

在重症监护病房采取有针对性的目标细菌去定植（decolonization）和普遍去定植都是防止卫生保健相关性感染（health care-associated infections）的候选策略，特别是对于那些由耐甲氧西林金黄色葡萄球菌（MRSA）引起的感染。这引起了Susan S. Huang博士等人的兴趣，他们经深入研究后发现，在常规ICU中，普遍去定植措施更为有效，有针对性的去定植或筛查分离措施也可以减少MRSA的临床分离和任何病原体引起的血液感染。相关论文发表于国际权威杂志NEJM 2013年6月在线版。

研究者进行了一项群组随机试验。入选医院被随机分配到三大策略组，每一个医院的ICU接受相同的策略。第一组实行集MRSA筛查和分离策略；第二组实行有针对性的去定植（即筛查分离MRSA携带者并对其进行去定植）；第三组实行普遍的去定植（即未经筛查并对所有患者都采取去定植措施）。研究人员采用比例风险模型来评估整个群组研究团队减少感染的差异情况。

一共有43家医院（介入期共纳入74个ICU，74256名患者）接受了随机分组。结果显示，在干预期，与基线水平比较， MRSA临床分离的模型风险比在第一组中每1000天的筛查为3.2 vs 4.3株，第二组为每1000天3.2 vs3.4株，第三组为2.1 vs 3.4株（P = 0.01）。在干预期中，与基线水平比较，任何病原体引起血流感染在三组中的危险比分别为0.99（粗患病率，4.1 vs 4.2每1000天感染数），0.78（3.7 vs 4.8），0.56（3.6 vs 6.1）。相较于针对性去定植组和筛查分离组，普遍去定植组的所有血液感染显著减少，MRSA血流感染也有所减少。MRSA血流感染率的减少与全部血流感染相似，但差异无显著性。有7例患者出现中度不良反应事件，均由氯已定治疗所引起。

结论：在常规ICU护理中，普遍去定植措施是更有效的，有针对性的目标去定植或筛查分离措施也可以减少MRSA的临床分离和任何病原体引起的血流感染。

专家意见：不要急着采用MRSA控制的新策略

委员会成员建议医院应该坚持现行控制院感的方法，并同时进行风险评估，来检验当前策略是否有效。只要当前院感率低于已发表文献数据，或者州内其他医院数据，那么这个医院就应该坚持当前控制院感的策略。医院应该维持现有的控制院内感染策略，而不是推进高价的新策略，疾病控制和流行病学专业委员的成员如是说。

该项研究表明，使用抗菌软膏和特殊香皂来杀灭MRSA的效果，比隔离和筛查病人要好。这个报告意义重大。它让医院停下来思考，医院是否有必要改变控制院感的策略。该报告中，比较了全美43家医院控制院内感染的策略，发现使用洗必泰和莫匹罗星广泛杀菌效果最佳，减少了约44%的血液感染，但采用该策略的医院极少。而使用隔离筛查的方法表现不佳，该方法反而在医院广为实施。医院们开始考虑，是否使用洗必泰和莫匹罗星广泛杀菌的方法，但是该方法耗资甚多。

立法机关可能会在将来立法，规定使用莫匹罗星广泛杀菌控制MRSA。但是这可能会促进新的耐药菌株的产生。

Targeted versus Universal Decolonization to Prevent ICU Infection
Background
Both targeted decolonization and universal decolonization of patients in intensive care units (ICUs) are candidate strategies to prevent health care–associated infections, particularly those caused by methicillin-resistant Staphylococcus aureus (MRSA).
Methods
We conducted a pragmatic, cluster-randomized trial. Hospitals were randomly assigned to one of three strategies, with all adult ICUs in a given hospital assigned to the same strategy. Group 1 implemented MRSA screening and isolation; group 2, targeted decolonization (i.e., screening, isolation, and decolonization of MRSA carriers); and group 3, universal decolonization (i.e., no screening, and decolonization of all patients). Proportional-hazards models were used to assess differences in infection reductions across the study groups, with clustering according to hospital.
Results
A total of 43 hospitals (including 74 ICUs and 74,256 patients during the intervention period) underwent randomization. In the intervention period versus the baseline period, modeled hazard ratios for MRSA clinical isolates were 0.92 for screening and isolation (crude rate, 3.2 vs. 3.4 isolates per 1000 days), 0.75 for targeted decolonization (3.2 vs. 4.3 isolates per 1000 days), and 0.63 for universal decolonization (2.1 vs. 3.4 isolates per 1000 days) (P=0.01 for test of all groups being equal). In the intervention versus baseline periods, hazard ratios for bloodstream infection with any pathogen in the three groups were 0.99 (crude rate, 4.1 vs. 4.2 infections per 1000 days), 0.78 (3.7 vs. 4.8 infections per 1000 days), and 0.56 (3.6 vs. 6.1 infections per 1000 days), respectively (P<0.001 for test of all groups being equal). Universal decolonization resulted in a significantly greater reduction in the rate of all bloodstream infections than either targeted decolonization or screening and isolation. One bloodstream infection was prevented per 54 patients who underwent decolonization. The reductions in rates of MRSA bloodstream infection were similar to those of all bloodstream infections, but the difference was not significant. Adverse events, which occurred in 7 patients, were mild and related to chlorhexidine.
Conclusions
In routine ICU practice, universal decolonization was more effective than targeted decolonization or screening and isolation in reducing rates of MRSA clinical isolates and bloodstream infection from any pathogen. (Funded by the Agency for Healthcare Research and the Centers for Disease Control and Prevention; REDUCE MRSA ClinicalTrials.gov number, NCT00980980.)