Schuetz A N, Hughes R L, Howard R M, Williams T C, Nolte F S, Jackson D, Ribner B S
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA.
Infect Control Hosp Epidemiol. 2009 May;30(5):461-6. doi: 10.1086/596613.
To investigate the marked increase noted over an 8-month period in the number of Legionella pneumophila isolates recovered from bronchoalveolar lavage fluid specimens obtained during bronchoscopy in our healthcare system.
Bronchoscopy suite that serves a 580-bed tertiary care center and a large, multisite, faculty practice plan with approximately 2 million outpatient visits per year.
Cultures of environmental specimens from the bronchoscopy suite were performed, including samples from the air and water filters, bronchoscopes, and the ice machine, with the aim of identifying Legionella species. Specimens were filtered and acid-treated and then inoculated on buffered charcoal yeast extract agar. Serogrouping was performed on all isolates recovered from patient and environmental samples.
All L. pneumophila isolates recovered from patients were serogroup 8, a serogroup that is not usually recovered in our facility. An epidemiologic investigation of the bronchoscopy suite revealed the ice machine to be contaminated with L. pneumophila serogroup 8. Patients were exposed to the organism as a result of a recently adopted practice in the bronchoscopy suite that involved directly immersing uncapped syringes of sterile saline in contaminated ice baths during the procedures. At least 1 patient was ill as a result of the pseudo-outbreak. Molecular typing of isolates recovered from patient and environmental samples revealed that the isolates were indistinguishable.
Extensive cleaning of the ice machine and replacement of the machine's water filter ended the pseudo-outbreak. This episode emphasizes the importance of using aseptic technique when performing invasive procedures, such as bronchoscopies. It also demonstrates the importance of reviewing procedures in all patient areas to ensure compliance with facility policies for providing a safe patient environment.
调查在我们的医疗系统中，支气管镜检查期间从支气管肺泡灌洗液体标本中分离出的嗜肺军团菌数量在8个月内显著增加的情况。
支气管镜检查室服务于一家拥有580张床位的三级护理中心以及一个大型、多地点的教职员工执业计划，每年约有200万门诊人次。
对支气管镜检查室的环境标本进行培养，包括空气和水过滤器、支气管镜及制冰机的样本，以鉴定军团菌种类。标本经过过滤和酸处理，然后接种于缓冲活性炭酵母浸出液琼脂上。对从患者和环境样本中分离出的所有菌株进行血清分型。
从患者中分离出的所有嗜肺军团菌菌株均为血清型8，该血清型在我们机构通常不会分离到。对支气管镜检查室的流行病学调查显示，制冰机被血清型8的嗜肺军团菌污染。由于支气管镜检查室最近采用的一种操作方法，即在操作过程中将未盖帽的无菌生理盐水注射器直接浸入受污染的冰浴中，患者接触到了该病原体。至少有1名患者因这次假暴发而患病。从患者和环境样本中分离出的菌株的分子分型显示，这些菌株无法区分。
对制冰机进行彻底清洁并更换其水过滤器，结束了这次假暴发。这一事件强调了在进行侵入性操作（如支气管镜检查）时使用无菌技术的重要性。它还表明了审查所有患者区域操作流程以确保符合机构提供安全患者环境政策的重要性。
