医院水环境军团菌污染及住院肺炎病例军团菌感染来源调查

目的 了解医院水环境军团菌污染及住院肺炎病例军团菌感染来源.方法 采集医院冷却塔水和管网末梢水共24件,进行军团菌分离培养.对90例住院肺炎病例进行问卷调查,深部痰液军团菌培养和荧光定量PCR检测,军团菌尿抗原和血抗体检测,明确军团菌发病情况及类型.对分离环境菌株和病人菌株进行了PFGE和SBT检测,进行病原体溯源.结果 医院冷却塔水军团菌阳性率100%(5/5),其中有2份水样军团菌浓度大于10³cfu/L;管网末梢水军团菌阳性率21.1%(4/19),其中有3份水样军团菌浓度大于10³cfu/L.余氯量平均0.03mg/L,污染军团菌血清型LP1,LP6.住院肺炎病例中军团菌肺炎阳性率15.6%(14/90),其中痰培养和PCR同时阳性1例,尿抗原阳性13例,社区获得性军团菌肺炎16.4%(11/67),医院获得性军团菌肺炎20.0%(3/15).分离环境与病人菌株血清型别和PFGE图谱分析均不一致,未能溯源.结论 医院水环境军团菌污染严重且污染浓度高,余氯浓度低于标准,存在发生医院内军团菌肺炎甚至暴发流行的严重隐患.建议定期监测医院水环境军团菌,对医院肺炎病人进行军团菌病相关检测,并研究具有可行性的消毒措施去除军团菌污染.

Contamination status of legionella in Hospital water environment and traceability investigation of legionella infection in hospital pneumonia cases

Objective To investigate the Contamination status of legionella in Hospital water environment and traceability investigation of legionella infection in hospital pneumonia cases. Methods 24 Cooling tower water and pipe network peripheral water samples of hospital were collected. The water samples were cultured for legionella. To know the situation and types of legionella infection,we survey 90 hospital pneumonia cases. Implementation of the questionnaire,deep sputum cultures and fluorescence quantitative PCR detection of legionella , urinary Antigen and serum antibody detection of legionella.To learn the source of legionella infection,the legionella strains which isolated from environment and cases were tested by the way of PFGE and SBT. Results The legionella positive rate of Cooling tower water was 100%(5/5), and 2 samples' legionella count were greater than 10³cfu/L. The legionella positive rate of pipe network peripheral water samples of hospital was 21.1%(4/19), and 3 samples' legionella count were more than 10³cfu/L.The average of residual chlorine in water was 0.03 mg/L.Legionella pollution serotypes were LP1, LP6. 15.6% (14/90) hospital pneumonia cases were infected by legionella. One case was positive by sputum culturing and PCR testing. 13 cases were positive by urinary antigen testing.16.4%(11/67)was CALs, 20.0%(3/15)was HALs.The strains separated from environment and patients,which spectrum and PFGE serotype were inconsistent. So, the source of legionella infection was unclear.Conclusion The investigated hospital have high levels contamination and high concentration of legionella, have lower residual chlorine concentration than the standard, which would likely to acquire legionellosis. We suggest regular monitoring legionella in hospital water environment, conduct Legionella disease related detection for hospital pneumonia cases, and disinfection of the water systems should be considered.