Warren David K, Guth Rebecca M, Coopersmith Craig M, Merz Liana R, Zack Jeanne E, Fraser Victoria J
Division of Infectious Diseases, Washington University School of Medicine, Barnes Jewish Hospital, Saint Louis, MO 63110, USA.
Infect Control Hosp Epidemiol. 2006 Oct;27(10):1032-40. doi: 10.1086/507919. Epub 2006 Aug 31.
Methicillin-resistant Staphylococcus aureus (MRSA) is a cause of healthcare-associated infections among surgical intensive care unit (ICU) patients, though transmission dynamics are unclear.
To determine the prevalence of MRSA nasal colonization at ICU admission, to identify associated independent risk factors, to determine the value of these factors in active surveillance, and to determine the incidence of and risk factors associated with MRSA acquisition.
Prospective cohort study.
Surgical ICU at a teaching hospital.
All patients admitted to the surgical ICU.
Active surveillance for MRSA by nasal culture was performed at ICU admission during a 15-month period. Patients who stayed in the ICU for more than 48 hours had nasal cultures performed weekly and at discharge from the ICU, and clinical data were collected prospectively. Of 1,469 patients, 122 (8%) were colonized with MRSA at admission; 75 (61%) were identified by surveillance alone. Among 775 patients who stayed in the ICU for more than 48 hours, risk factors for MRSA colonization at admission included the following: hospital admission in the past year (1-2 admissions: adjusted odds ratio [aOR], 2.60 [95% confidence interval {CI}, 1.47-4.60]; more than 2 admissions: aOR, 3.56 [95% CI, 1.72-7.40]), a hospital stay of 5 days or more prior to ICU admission (aOR, 2.54 [95% CI, 1.49-4.32]), chronic obstructive pulmonary disease (aOR, 2.16 [95% CI, 1.17-3.96]), diabetes mellitus (aOR, 1.87 [95% CI, 1.10-3.19]), and isolation of MRSA in the past 6 months (aOR, 8.18 [95% CI, 3.38-19.79]). Sixty-nine (10%) of 670 initially MRSA-negative patients acquired MRSA in the ICU (corresponding to 10.7 cases per 1,000 ICU-days at risk). Risk factors for MRSA acquisition included tracheostomy in the ICU (aOR, 2.18 [95% CI, 1.13-4.20]); decubitus ulcer (aOR, 1.72 [95% CI, 0.97-3.06]), and receipt of enteral nutrition via nasoenteric tube (aOR, 3.73 [95% CI, 1.86-7.51]), percutaneous tube (aOR, 2.35 [95% CI, 0.74-7.49]), or both (aOR, 3.33 [95% CI, 1.13-9.77]).
Active surveillance detected a sizable proportion of MRSA-colonized patients not identified by clinical culture. MRSA colonization on admission was associated with recent healthcare contact and underlying disease. Acquisition was associated with potentially modifiable processes of care.
耐甲氧西林金黄色葡萄球菌（MRSA）是外科重症监护病房（ICU）患者发生医疗相关感染的一个病因，但其传播动态尚不清楚。
确定ICU入院时MRSA鼻腔定植的患病率，识别相关的独立危险因素，确定这些因素在主动监测中的价值，并确定MRSA感染的发生率及相关危险因素。
前瞻性队列研究。
一家教学医院的外科ICU。
所有入住外科ICU的患者。
在15个月期间，于ICU入院时通过鼻腔培养对MRSA进行主动监测。在ICU停留超过48小时的患者每周及在ICU出院时进行鼻腔培养，并前瞻性收集临床数据。1469例患者中，122例（8%）入院时被MRSA定植；仅通过监测发现75例（61%）。在775例在ICU停留超过48小时的患者中，入院时MRSA定植的危险因素包括：过去一年入院（1 - 2次入院：校正比值比[aOR]，2.60[95%置信区间{CI}，1.47 - 4.60]；超过2次入院：aOR，3.56[95%CI，1.72 - 7.40]），ICU入院前住院5天或更长时间（aOR，2.54[95%CI，1.49 - 4.32]），慢性阻塞性肺疾病（aOR，2.16[95%CI，1.17 - 3.96]），糖尿病（aOR，1.87[95%CI，1.10 - 3.19]），以及过去6个月内分离出MRSA（aOR，8.18[95%CI，3.38 - 19.79]）。670例初始MRSA阴性的患者中有69例（10%）在ICU获得MRSA（相当于每1000个ICU危险日有10.7例）。MRSA感染的危险因素包括在ICU行气管切开术（aOR，2.18[95%CI，1.13 - 4.20]）；压疮（aOR，1.72[95%CI，0.97 - 3.06]），以及通过鼻肠管（aOR，3.73[95%CI，1.86 - 7.51]）、经皮管（aOR，2.35[95%CI，0.74 - 7.49]）或两者同时接受肠内营养（aOR，3.33[95%CI，1.13 - 9.77]）。
主动监测发现了相当比例的临床培养未识别出的MRSA定植患者。入院时MRSA定植与近期医疗接触及基础疾病相关。感染与可能可改变的护理过程相关。
