Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN, USA.
J Clin Gastroenterol. 2012 Nov-Dec;46(10):846-9. doi: 10.1097/MCG.0b013e3182432273.
To evaluate the yield of repeat stool polymerase chain reaction (PCR) testing in patients with suspected Clostridium difficile infection (CDI).
CDI is a major challenge in health care due to its frequent occurrence and high associated costs. Enzyme immunoassay and PCR are commonly performed diagnostic tests for CDI.
Our microbiology laboratory database was queried from January 1, 2008 to June 30, 2010 for all patients who underwent PCR stool testing for suspected CDI. Data collected included age, sex, number of stool tests performed within a 14-day period after the first test, and location of patient (inpatient vs. outpatient). Analyses were performed using JMP version 9.0.1.
PCR testing was performed in 15,515 patients. The median age was 58.3 years (range, 10 d to 104.3 y) and 46.2% of patients were women. Repeat testing was infrequent; 87.3% of patients had testing performed only once in a 14-day period. Increased age, male sex, and inpatient location were predictors of repeat testing. The median time between an initial test and the first repeat test was 5 days. After an initial negative test, the percentage of patients having a subsequent positive test was low (2.7% in 7 d and 3.2% in 14 d). The percentage of repeat tests that was positive within 7 days (2.9%) was lower than the percentage that was positive from day 8 to day 14 (4.8%, P=0.05).
Repeat testing for C. difficile has a low yield, and patients with an initial negative test should not routinely be retested.
评估疑似艰难梭菌感染（CDI）患者重复粪便聚合酶链反应（PCR）检测的效果。
由于 CDI 频繁发生且相关费用高，因此它是医疗保健中的一个主要挑战。酶联免疫吸附试验和 PCR 是常用于 CDI 的诊断检测方法。
我们的微生物实验室数据库从 2008 年 1 月 1 日至 2010 年 6 月 30 日对所有进行 PCR 粪便检测以疑似 CDI 的患者进行了查询。收集的数据包括年龄、性别、首次检测后 14 天内进行的粪便检测次数以及患者的位置（住院患者与门诊患者）。使用 JMP 版本 9.0.1 进行分析。
对 15515 名患者进行了 PCR 检测。中位年龄为 58.3 岁（范围 10 天至 104.3 岁），46.2%的患者为女性。重复检测的频率较低；87.3%的患者在 14 天内仅进行了一次检测。年龄较大、男性和住院患者的位置是重复检测的预测因素。初始检测与首次重复检测之间的中位时间为 5 天。初始检测呈阴性后，随后呈阳性的患者比例较低（7 天内为 2.7%，14 天内为 3.2%）。在 7 天内呈阳性的重复检测比例（2.9%）低于第 8 天至第 14 天呈阳性的比例（4.8%，P=0.05）。
艰难梭菌的重复检测效果不佳，初始检测呈阴性的患者不应常规进行重复检测。
