某醫學中心內科加護病房多重抗藥性鮑氏不動桿菌群突發之調查處理

Investigation and Management of an Outbreak of Multiple Drug-resistant Acinetobacter baumannii in a Medical Intensive Care Unit in Northern Taiwan

2005 年7 至12 月中旬在某醫學中心內科加護病房，微生物培養發現多重抗藥性鮑氏不動桿菌(multiple drug-resistant Acinetobacter baumannii; MDRAB) 感染造成的群突發事件。這期間共有7 位MDRAB 醫療照護相關感染及6 位呼吸道移生的病人；5 位得到肺炎（其中2 位合併有繼發性菌血症），另外有2 位得到原發性菌血症。流行期間，環境檢體共採檢101 件，其中20 件長出MDRAB，分別是採自呼吸器面板（7 件）、甦醒器（5 件）、抽痰壓力表面板（3件）、工作車檯面（2 件）、EKG 面版（1 件）、病歷封面（1 件）及急救車檯面（1 件）等。醫護人員28 件手部採檢檢體中，有2 件長出MDRAB。將所收集到的MDRAB 菌株以脈衝電泳法(pulsed-field gel electrophoresis; PFGE ) 作基因分型鑑定，共可分出八種基因分型（A-H型），其中A 型、B 型為引起此群突發事件的主要流行菌株。13 株臨床菌株中，A 型引起3 人感染、4 人移生，B 型引起2人感染、1 人移生。而20 件環境菌株中，16 株為A 型；2 株來自醫護人員的菌株，也屬A 型。因在醫療儀器、環境檢體甚至工作人員手上均採檢到與病人相同的MDRAB 基因型（A 型與B 型），因此推論這是一起經手部交叉感染而引發的群突發事件。此次群突發處理措施為，包括加強員工教育訓練（包括手部衛生宣導及無菌技術操作）將MDRAB 感染與移生病人予以集中照護(cohort care) 與隔離，針對容易污染的醫療儀器設備環境表面，加強清潔消毒。並於病床區增設乾式洗手液與加強動線管制（內科加護病房地面畫紅線、黃線作為隔離區與緩衝區之區分），該單位自2005 年12 月中旬後，無MDRAB 的感染新案發生。

In this study, we have described an outbreak of multiple drug-resistant Acinetobacter baumannii (MDRAB) that occurred in a medical intensive care unit (MICU) between July and December, 2005. The clinical symptoms of the outbreak included pneumonia (5 cases, 2 of which also showed secondary bacteremia), primary bacteremia (2 cases), and respiratory tract colonization (6 cases). A total of 101 environmental specimens and 28 hand wash samples of health care workers (HCWs) were collected for the epidemiological investigation. Twenty MDRAB isolates were recovered from the environmental samples, and 2 were recovered from the samples from HCWs; the contaminated environmental samples included those obtained from the Ambu bag, ventilator screen, sputum-suctioning devices, EKG monitor, chart cover, and surface of the emergency cart. Pulsed-field gel electrophoresis (PFGE) showed that 2 major MDRAB clones accounted for this outbreak (5 nosocomial infections and 5 colonizations). PFGE revealed that most of the environmental and hand swab MDRAB isolates were the same endemic strains.[Author1] Cross-transmission via transient contamination of the environmental surfaces and hands was the major reason for this outbreak. The control measures were increased staff education, hand hygiene, cohort isolation, aggressive cleaning of the environment surfaces, and strict transmission control. Thus, the outbreak was terminated by adopting a multidisciplinary approach.