Background

The Department of Veterans Affairs implemented an active surveillance program for methicillin-resistant Staphylococcus aureus (MRSA) in 2007 in which acute care inpatients are tested for MRSA carriage on admission, unit-to-unit transfer, and discharge. Using these data, we followed patients longitudinally to estimate the difference in infection rates for those who were not colonized, those who were colonized on admission (importers), and those who acquired MRSA during their stay. We examined MRSA infections that occurred prior to discharge and at 30, 90, 180, and 365 days after discharge.

Methods

We constructed a dataset of 985626 first admissions from January 2008 through December 2015 who had surveillance tests performed for MRSA carriage. We performed multivariable Cox proportional hazards and logistic regression models to examine the relationship between MRSA colonization status and infection.

Results

The MRSA infection rate across the predischarge and 180-day postdischarge time period was 5.5% in importers and 7.0% in acquirers without a direct admission to the intensive care unit (ICU) and 11.4% in importers and 11.7% in acquirers who were admitted directly to the ICU. The predischarge hazard ratio for MRSA infection was 29.6 (95% confidence interval [CI], 26.5–32.9) for importers and 28.8 (95% CI, 23.5–35.3) for acquirers compared to those not colonized. Fully 63.9% of all MRSA pre- and postdischarge infections among importers and 61.2% among acquirers occurred within 180 days after discharge.

Conclusions

MRSA colonization significantly increases the risk of subsequent MRSA infection. In addition, a substantial proportion of MRSA infections occur after discharge from the hospital.

中文翻译：

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耐甲氧西林金黄色葡萄球菌定植和院前和院后出院感染风险

背景

退伍军人事务部于2007年实施了耐甲氧西林金黄色葡萄球菌（MRSA）的主动监视程序，其中对急诊住院患者入院，单位转移和出院时进行了MRSA携带测试。使用这些数据，我们纵向跟踪了患者，以估计未定植者，入院时定植者（进口商）和在住院期间获得MRSA的感染率的差异。我们检查了出院前以及出院后30、90、180和365天发生的MRSA感染。

方法

我们构建了从2008年1月到2015年12月的985626例首次入院的数据集，他们对MRSA运送进行了监控测试。我们进行了多变量Cox比例风险和逻辑回归模型，以检验MRSA定植状态与感染之间的关系。

结果

出院前和出院后180天期间，未直接进入重症监护病房（ICU）的进口商的MRSA感染率分别为5.5％和7.0％，而直接入院的进口商的MRSA感染率为11.4％，进口商为11.7％。到ICU。与未定殖的收购者相比，进口商的MRSA感染的出院前危险比为29.6（95％置信区间[CI]，26.5-32.9），对收购者而言为28.8（95％CI，23.5-35.3）。进口商出院后180天内，全部MRSA出院前和出院后感染中有63.9％，收购者中有61.2％。

结论

MRSA定植显着增加了随后MRSA感染的风险。此外，出院后发生相当大比例的MRSA感染。