加護病房多重抗藥性鮑氏不動桿菌群突發：強調群突發時需控制醫院環境之汙染

Investigation and Intervention of a Multidrug-resistant Acinetobacter baumannii Outbreak in an Intensive Care Unit: An Emphasis on Environment Contamination

2009年11月至2010年2月期間，某區域醫院計有11床的內科加護病房發生了多重抗藥性鮑氏不動桿菌（multidrug-resistant Acinetobacter baumannii, MDRAB）群聚移生與感染現象。醫院感控人員經由例行性院內感染監測發現此事且及時通知加護病房同仁，依現場觀察的結果進行洗手衛生監控與接觸隔離措施。共有9位病患分別自痰、中心靜脈導管、血液、胸水、支氣管鏡沖洗液培養出MDRAB，全部個案皆曾使用廣效性抗生素與呼吸器支持治療。為釐清傳播途徑與移生或感染菌株的來源，進行環境採檢。加護病房環境採檢的38健檢體中，有4件為MDRAB菌株，分別來自人工急救甦醒球、床欄、醫師專用桌上型電腦鍵盤、筆記型電腦鍵盤。這四株MDRAB環境菌株顯示與6位病患的MDRAB屬同一脈衝電泳分型，也都具有blaOXA-72抗藥性基因。經由加強感控措施與洗手遵從性的監控，之後十個月沒有MDRAB群突發發生。本研究顯示病患病房環境的污染和醫院同仁的電腦鍵盤與MDRAB群突發具相關性。積極介入感控措施可以使MDRAB群突發獲得有效控制。

From November 2009 to February 2010, a cluster of multidrug-resistant Acinetobacter baumannii (MDRAB) colonizations/infections was identified and investigated at an 11-bed intensive care unit (ICU) of a Taiwan regional hospital. Infection control personnel had identified this event through routine surveillance, and ICU staffs were informed immediately. On the basis of the results of on-site observation, hand hygiene and contact precautions were reinforced. MDRAB was isolated from the sputum, central venous catheter, blood samples, pleural effusion, and bronchial washing fluid of 9 patients. All patients received broad-spectrum antimicrobial therapy and ventilatory support. To elucidate the mode of transmission and source of colonization/infection, microbial surveillance of the environment was undertaken. Among 38 swab cultures from ICU subjects, MDRAB was isolated from an Ambu bag, bed rails, a physician’s desktop computer keyboard, and a physician’s notebook keyboard. On the basis of pulsed-field gel electrophoresis findings, the pulsotype of the 4 MDRAB environment isolates was identical to that of the clinical MDRAB isolates from 6 patients. All of these isolates carried the blaOXA-72 gene. The cluster was controlled after infection control measures were reinforced and compliance was monitored. This study showed that contamination of the patient environment and the computer keyboards of hospital staff were associated with the MDRAB outbreak. Infection control interventions can stop further transmission.