The Effect of Rapid Screening for Methicillin-Resistant Staphylococcus aureus (MRSA) on the Identification and Earlier Isolation of MRSA-Positive Patients
The Effect of Rapid Screening for Methicillin-Resistant Staphylococcus aureus (MRSA) on the Identification and Earlier Isolation of MRSA-Positive Patients
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DOI：
10.1086/651093
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发表时间：
2010-04-01
影响因子：
4.5
通讯作者：
Humphreys, Hilary
中科院分区：
文献类型：
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作者：
Creamer, Eilish;Dolan, Anthony;Humphreys, Hilary
目标. (1)为了确定聚合酶链反应（PCR）检测试剂盒快速筛查是否能提前隔离有耐甲氧西林金黄色葡萄球菌（MRSA）定植风险的患者，（2）评估对常规MRSA筛查方案的依从性，（3）通过与培养物进行比较，确认Xpert MRSA实时PCR检测试剂盒（Cepheid）的诊断准确性，和（4）比较PCR检测结果与培养结果的周转时间。在一家拥有700张床位的急性三级护理转诊医院进行的前后研究。研究周期为（1）PCR检测开始前5周，（2）使用PCR检测时10周，（3）PCR检测停止后5周。在489例高危患者中，第1阶段60例患者中有20例（33%）分离出MRSA，第2阶段349例患者中有77例（22%）分离出MRSA，第3阶段80例患者中有18例（23%）分离出MRSA。82名高危患者中有22名（27%）在第1阶段未接受筛查，而389名高危患者中有40名（10%）在第2阶段未接受筛查（P <0.001）。与第2阶段相比，第1阶段和第3阶段更多的MRSA阳性患者被预先隔离（140例中34例[24%]对389例中28例[8%]; P < .001）;但是，在此情况下，在第2阶段，在通知MRSA阳性结果后，隔离了更多MRSA阳性患者（47/349 [13%]）与第1和第3阶段（2/140 [1%]; P < .001）相比。PCR检测的敏感性、特异性、阳性预测值和阴性预测值分别为95%、97%、82%和99%。从实验室收到标本到PCR检测结果的平均周转时间为2.6小时。使用Xpert MRSA PCR检测试剂盒进行快速筛查有助于遵守筛查政策，并更早地隔离MRSA阳性患者。不一致的结果证实，PCR检测应作为一种筛查工具，而不是作为一种诊断工具。
OBJECTIVES. (1) To determine whether rapid screening with polymerase chain reaction (PCR) assays leads to the earlier isolation of patients at risk for methicillin-resistant Staphylococcus aureus (MRSA) colonization, (2) to assess compliance with routine MRSA screening protocols, (3) to confirm the diagnostic accuracy of the Xpert MRSA real-time PCR assay (Cepheid) by comparison with culture, and (4) to compare turnaround times for PCR assay results with those for culture results.DESIGN. Before-and-after study conducted in a 700-bed acute tertiary care referral hospital. Study periods were (1) a 5-week period before PCR testing began, (2) a 10-week period when the PCR assay was used, and (3) a 5-week period after PCR testing was discontinued.RESULTS. Among 489 at-risk patients, MRSA was isolated from 20 (33%) of 60 patients during period 1, 77 (22%) of 349 patients during period 2, and 18 (23%) of 80 patients during period 3. Twenty-two (27%) of 82 at-risk patients were not screened during period 1, compared with 40 (10%) of 389 at-risk patients not screened during period 2 (P < .001). More MRSA-positive patients were preemptively isolated during periods 1 and 3 compared with period 2 (34 [24%] of 140 vs 28 [8%] of 389; P < .001); however, more MRSA-positive patients were isolated after notification of MRSA-positive results during period 2 (47 [13%] of 349) compared with periods 1 and 3 (2 [1%] of 140; P < .001). The sensitivity, specificity, positive predictive value, and negative predictive value of the PCR assay were 95%, 97%, 82%, and 99%, respectively. The mean turnaround time from receipt of specimens in the laboratory to PCR assay result was 2.6 hours.CONCLUSIONS. Rapid screening with the Xpert MRSA PCR assay facilitated compliance with screening policies and the earlier isolation of MRSA-positive patients. Discrepant results confirm that PCR testing should be used as a screening tool rather than as a diagnostic tool.