Department of Medicine, Washington University School of Medicine, St Louis, MO, USA.
Am J Infect Control. 2012 May;40(4):349-53. doi: 10.1016/j.ajic.2011.04.002. Epub 2011 Jul 27.
Clostridium difficile infection (CDI) is most commonly diagnosed using toxin enzyme immunoassays (EIAs). A sudden decrease in CDI incidence was noted after a change in the EIA used at Barnes-Jewish Hospital in St Louis. The objective of this study was to determine whether the decreased CDI incidence related to the change in EIA resulted in adverse patient outcomes.
Electronic hospital databases were used to collect data on demographics, outcomes, and treatment of inpatients who had a C difficile toxin assay performed between January 4, 2009, and April 3, 2009 (period A, preassay change) and between May 21, 2009, and August 17, 2009 (period B, postassay change).
Assays were positive in 240 of 1,221 patients (19.7%) during period A and in 106 of 1160 patients (9.1%) during period B (P < .01). There was no difference in mortality or discharge to hospice between the 2 periods (10.3% vs 10.1%; P = .90). Patients tested in period B were less likely to receive metronidazole or oral vancomycin (P < .01).
The new EIA resulted in fewer positive tests and reduced anti-CDI therapy. There was no difference in mortality between the 2 periods, suggesting that the decreased incidence was due to increased assay specificity, not decreased sensitivity.
艰难梭菌感染（CDI）最常通过毒素酶免疫分析（EIA）进行诊断。在圣路易斯巴恩斯-犹太医院改变 EIA 后，注意到 CDI 的发病率突然下降。本研究的目的是确定 EIA 改变与 CDI 发病率下降是否与患者不良预后有关。
使用电子医院数据库收集 2009 年 1 月 4 日至 4 月 3 日（检测前改变期，A 期）和 2009 年 5 月 21 日至 8 月 17 日（检测后改变期，B 期）期间接受艰难梭菌毒素检测的住院患者的人口统计学、结局和治疗数据。
A 期有 1221 例患者中有 240 例（19.7%）检测结果阳性，B 期有 1160 例患者中有 106 例（9.1%）检测结果阳性（P<0.01）。两个时期的死亡率或临终关怀出院率没有差异（10.3% vs 10.1%；P=0.90）。B 期接受检测的患者接受甲硝唑或口服万古霉素治疗的可能性较低（P<0.01）。
新的 EIA 导致阳性检测结果减少和抗 CDI 治疗减少。两个时期的死亡率没有差异，这表明发病率下降是由于检测特异性增加，而不是敏感性降低。
