某综合ICU耐碳青霉烯鲍曼不动杆菌下呼吸道医院感染暴发调查

目的调查某院综合重症监护病房（ICU）一起由耐碳青霉烯类鲍曼不动杆菌（CRAB）引起的疑似下呼吸道医院感染暴发流行的原因，为有效控制医院感染提供科学依据。方法对2014年3月4-23日该综合ICU CRAB感染病例进行流行病学调查和现场环境卫生学监测，并积极采取预防控制措施。结果共发生CRAB医院感染7例，流行期间总住院日数160 d，下呼吸道CRAB医院感染发病密度为43.75‰（7/160），02床收治的5例患者中4例发生CRAB下呼吸道医院感染。单因素分析显示，使用常规吸痰是重要的危险因素；物体表面细菌菌落数合格率为31.75%(20/63)。02床吸引装置外架培养出CRAB，该菌与7例患者痰培养CRAB耐药谱相同。通过采取一系列控制措施，2014年3月24日后未再出现CRAB感染病例，此次CRAB暴发流行得到有效控制。结论此次疑似医院感染暴发可能原因为吸引装置外架污染CRAB后消毒不彻底，通过医务人员吸痰操作水平传播。ICU环境物体表面的清洁消毒对于预防医院感染至关重要。

An outbreak of healthcare associated carbapenem resistant Acinetobacter baumannii lower respiratory tract infection in an intensive care unit

ObjectiveTo investigate the causes of a suspected outbreak of lower respiratory tract infection (LRTI) caused by carbapenem resistant Acinetobacter baumannii (CRAB) in the general intensive care unit(ICU) of a hospital, and provide scientific evidence for effective control of healthcare associated infection(HAI).MethodsEpidemiological investigation on patients infected with CRAB and on site monitoring on ICU environmental hygiene from March 4 to 23,2014 were performed, active prevention and control measures were taken.ResultsA total of 7 patients developed CRAB infection, the total length of stay during epidemic period were 160 days, the infection density of LRTI was 43.75‰（7/160）, 4 of 5 patients at No.02 bed had CRAB LRTI. Univariate analysis revealed that adopting conventional sputum suction procedure was a risk factor; the qualified rate of bacterial count on the object surfaces was 31.75% (20/63). CRAB was also isolated from outer frame of suction device of No.02 bed, which had the same antimicrobial pattern as CRAB from 7 patients’ sputum. After taking a series of controlling measures, there was no CRAB infection case after March 24,2014, this outbreak was effectively controlled.ConclusionThis suspected HAI outbreak may be caused by inadequate disinfection of outer frame of suction device contaminated by CRAB, and horizontally transmitted through manipulation of sputum suction by health care workers. Clean and disinfection of ICU environmental object surfaces is of great importance for preventing HAI.