Stout Janet E, Yu Victor L
Special Pathogens Laboratory, Veterans Affairs Medical Center, Pittsburg, Pennsylvania 15240, USA.
Infect Control Hosp Epidemiol. 2003 Aug;24(8):563-8. doi: 10.1086/502251.
Hospital-acquired legionnaires' disease can be prevented by disinfection of hospital water systems. This study assessed the long-term efficacy of copper-silver ionization as a disinfection method in controlling Legionella in hospital water systems and reducing the incidence of hospital-acquired legionnaires' disease. A standardized, evidence-based approach to assist hospitals with decision making concerning the possible purchase of a disinfection system is presented.
The first 16 hospitals to install copper-silver ionization systems for Legionella disinfection were surveyed. Surveys conducted in 1995 and 2000 documented the experiences of the hospitals with maintenance of the system, contamination of water with Legionella, and occurrence of hospital-acquired legionnaires' disease. All were acute care hospitals with a mean of 435 beds.
All 16 hospitals reported cases of hospital-acquired legionnaires' disease prior to installing the copper-silver ionization system. Seventy-five percent had previously attempted other disinfection methods including superheat and flush, ultraviolet light, and hyperchlorination. By 2000, the ionization systems had been operational from 5 to 11 years. Prior to installation, 47% of the hospitals reported that more than 30% of distal water sites yielded Legionella. In 1995, after installation, 50% of the hospitals reported 0% positivity, and 43% still reported 0% in 2000. Moreover, no cases of hospital-acquired legionnaires' disease have occurred in any hospital since 1995.
This study represents the final step in a proposed 4-step evaluation process of disinfection systems that includes (1) demonstrated efficacy of Legionella eradication in vitro using laboratory assays, (2) anecdotal experiences in preventing legionnaires' disease in individual hospitals, (3) controlled studies in individual hospitals, and (4) validation in confirmatory reports from multiple hospitals during a prolonged time (5 to 11 years in this study). Copper-silver ionization is now the only disinfection modality to have fulfilled all four evaluation criteria.
医院获得性军团病可通过医院水系统消毒来预防。本研究评估了铜银离子化作为一种消毒方法在控制医院水系统中军团菌及降低医院获得性军团病发病率方面的长期效果。提出了一种标准化的、基于证据的方法，以协助医院就可能购买消毒系统做出决策。
对首批16家安装铜银离子化系统用于军团菌消毒的医院进行了调查。1995年和2000年开展的调查记录了这些医院在系统维护、军团菌水污染以及医院获得性军团病发生情况方面的经历。所有医院均为平均拥有435张床位的急症医院。
所有16家医院在安装铜银离子化系统之前均报告过医院获得性军团病病例。75%的医院此前曾尝试过其他消毒方法，包括过热冲洗、紫外线照射和高浓度氯化消毒。到2000年时，离子化系统已运行5至11年。安装前，47%的医院报告称超过30%的远端水点检测出军团菌。1995年安装后，50%的医院报告阳性率为0%，2000年仍有43%的医院报告阳性率为0%。此外，自1995年以来，任何一家医院均未发生过医院获得性军团病病例。
本研究是消毒系统拟议的四步评估过程中的最后一步，该过程包括：（1）使用实验室检测方法在体外证明根除军团菌的效果；（2）个别医院预防军团病的轶事性经验；（3）个别医院的对照研究；（4）在多家医院的验证报告中进行长时间（本研究为5至11年）的验证。铜银离子化目前是唯一满足所有四项评估标准的消毒方式。
