Division of Infectious Diseases and Hospital Epidemiology, University Hospital Basel, Switzerland.
Clin Infect Dis. 2012 Dec;55(11):1505-11. doi: 10.1093/cid/cis770. Epub 2012 Sep 5.
Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae are emerging worldwide. Contact isolation is recommended; however, little is known about the rate of transmission without contact isolation in the non-epidemic setting. Therefore, we aimed to estimate the rate of spread (R(0)) of ESBL-producing Enterobacteriaceae in a tertiary care center with 5 intensive care units.
In this observational cohort study performed from June 1999 through April 2011, all patients at the University Hospital Basel, Switzerland, who were hospitalized in the same room as a patient colonized or infected with an ESBL-producing Enterobacteriaceae for at least 24 hours (index case) were screened for ESBL carriage by testing of rectal swab samples, swab samples from open wounds or drainages, and urine samples from patients with foley catheters. Strains with phenotypic evidence for ESBL were confirmed by polymerase chain reaction. Nosocomial transmission was assumed when the result of screening for ESBL carriage in a contact patient was positive and molecular typing by pulsed-field gel electrophoresis (PFGE) revealed clonal relatedness with the strain from the index patient.
Active screening for ESBL carriage could be performed in 133 consecutive contact patients. Transmission confirmed by PFGE occurred in 2 (1.5%) of 133 contact patients, after a mean exposure to the index case of 4.3 days.
The estimated rate of spread of ESBL-producing Enterobacteriaceae-in particular, Escherichia coli-was low in a tertiary care university-affiliated hospital with high levels of standard hygiene precautions. The low level of nosocomial transmission and the rapid emergence of community-acquired ESBL challenge the routine use of contact isolation in a non-epidemic setting, saving resources and potentially improving patient care.
产超广谱β-内酰胺酶（ESBL）的肠杆菌科细菌正在全球范围内出现。推荐进行接触隔离；然而，在非流行环境中，没有接触隔离时的传播速率知之甚少。因此，我们旨在估计在有 5 个重症监护病房的三级保健中心中，产 ESBL 的肠杆菌科细菌的传播速率（R(0)）。
在这项于 1999 年 6 月至 2011 年 4 月进行的观察性队列研究中，瑞士巴塞尔大学医院的所有患者，如果与定植或感染产 ESBL 的肠杆菌科细菌的患者在同一病房住院至少 24 小时（索引病例），则通过直肠拭子样本、开放伤口或引流拭子样本以及带 Foley 导管的患者尿液样本进行 ESBL 携带的筛查，以检测 ESBL 携带。通过聚合酶链反应对表现出 ESBL 表型证据的菌株进行确认。当接触患者的 ESBL 携带筛查结果为阳性，且脉冲场凝胶电泳（PFGE）的分子分型显示与索引患者的菌株具有克隆相关性时，假定为医院内传播。
可以对 133 例连续接触患者进行主动 ESBL 携带筛查。通过 PFGE 确认的传播发生在 133 例接触患者中的 2 例（1.5%），接触索引病例的平均时间为 4.3 天。
在三级保健大学附属医院中，高水平的标准卫生预防措施下，产 ESBL 的肠杆菌科细菌，尤其是大肠杆菌的传播速率估计较低。医院内传播的低水平和社区获得性 ESBL 的快速出现，对非流行环境中常规使用接触隔离提出了挑战，节省了资源并可能改善患者的护理。
