抗藥性鮑氏不動桿菌在感染症患者週遭盛行
作者：Emma Hitt, PhD
出處：WebMD醫學新聞
March 23, 2010 (亞特蘭大) — 新研究認為，感染多重抗藥性鮑氏不動桿菌(MDR-AB)病患的週遭環境有半數左右的時間受到汙染。
巴爾的摩馬里蘭大學流行病學與預防醫學助理教授Kerri A. Thom醫師在發表時表示，健康照護工作者在例行性病患照護時接觸的表面，包括治療車、輸注幫浦、呼吸器觸控板，往往都遭到污染。
她在第5屆十年一次的國際研討會2010健康照護相關感染症會議中發表研究發現。
根據Thom醫師等人指出，環境在傳播MDR-AB的角色還未被完全暸解，研究者於2008年10月8日至2009年1月28日間，在單一機構的加護病房對已經知道有MDR-AB菌落或感染有該菌的病患進行了前瞻世代研究。
研究者在50間房間、每間房間的10個表面用拭子取下化驗標本，共獲得478個樣本，培養這些樣本且以脈衝場凝膠電泳(pulsed-field gel electrophoresis)評估。
這些樣本中，9.8%為鮑氏不動桿菌陽性，這50個房間中，約半數房間有至少一處取樣地點為MDR-AB陽性， 最常被污染的表面有治療車(20%)、地板(16%)、輸注幫浦(14%)、呼吸器觸控板(11.4%)以及床欄架(10.2%)。
研究者也根據取樣的陽性培養時間進行分析，比較了之前2個月內收集的培養樣本(最近組)以及收集時間超過2個月的樣本(久遠組)，他們發現，相較於久遠組，最近組有MDR-AB的病患(78%)比較不會污染他們的環境。
在鮑氏不動桿菌陽性環境的24個病患中，20人最近有MDR-AB，其中的17個案例，病患和環境分離出的細菌基因相似。
Thom醫師向Medscape Infectious Diseases表示，鮑氏不動桿菌是重要的醫院病源，在格蘭氏陰性菌中相當獨特的一種菌，在環境中可以存在相當長的一段期間。
根據Thom醫師表示，健康照護者經常接觸的表面(治療車、輸注幫浦、呼吸器)是最常被污染的，可能會藉由健康照護工作者的手造成病患間的傳染。
她指出，這些結果提供更多證據支持需做到100%的手部消毒，以及須嚴格落實例行性清潔與環境表面消毒。
佛羅里達邁阿密大學Miller醫學院感染症小組L. Silvia Munoz-Price醫師指出，這些發現確認了感染鮑氏不動桿菌之病患附近的環境表面事實上也受到此菌的汙染。
根據Munoz-Price醫師表示，研究結果可用來告知環境清潔人員以及健康照護工作者有關徹底清潔和遵守手部消毒的重要性。
她重申，靠近感染有或有鮑氏不動桿菌菌落之病患的環境表面，必須每天廣泛清潔一次，以減少院內感染的可能性。
國家健康研究中心資助本研究，Thom 醫師與 Munoz-Price 醫師皆宣告沒有相關財務關係。
第5屆十年一次的國際研討會、2010健康照護相關感染症(Healthcare-Associated Infections (ICHAI))會議：摘要?673。發表於2010年3月20日。
Drug-Resistant A Baumannii Prevalent in Surroundings of Infected Patients
By Emma Hitt, PhD
Medscape Medical News
March 23, 2010 (Atlanta, Georgia) — The environment surrounding patients infected with multidrug-resistant Acinetobacter baumannii (MDR-AB) is contaminated about half of the time, new study findings suggest.
"Surfaces touched by healthcare workers during routine patient care, including supply carts, infusion pumps, and ventilator touch pads, are commonly contaminated," said Kerri A. Thom, MD, MS, assistant professor of epidemiology and preventive medicine at the University of Maryland in Baltimore, during her presentation.
She presented the findings here at the Fifth Decennial International Conference on Healthcare-Associated Infections 2010.
According to Dr. Thom and colleagues, the role of the environment in the transmission of MDR-AB is "incompletely understood." The researchers conducted a prospective cohort study of patients known to be colonized or infected with MDR-AB in the intensive care unit of a single institution from October 8, 2008 to January 28, 2009.
A total of 478 samples from 50 rooms were collected by swabbing 10 surfaces in each room. Samples were cultured and assessed with pulsed-field gel electrophoresis.
Of the samples, 9.8% were positive for A?baumannii. About half of the rooms were positive for MDR-AB at 1 or more sites tested. In each of the 50 rooms, the surfaces most likely to be contaminated were supply carts (20%), floors (16%), infusion pumps (14%), ventilator touch pads (11.4%), and bed rails (10.2%).
The researchers also analyzed the findings according to the time the positive culture was collected, comparing cultures collected within the previous 2 months (recent history) with those collected more than 2 months previous (remote history). They found that patients with a recent history of MDR-AB (78%) were no more likely to contaminate their environment than those with a remote history.
Among the 24 patients with an environmental culture positive for A?baumannii, 20 had a recent history of MDR-AB. In 17 of those cases, the patient and environmental isolates were genetically similar.
"A?baumannii is an important hospital pathogen," Dr. Thom told Medscape Infectious Diseases. "This organism is unique among Gram-negative pathogens, in that it has been shown to persist in the environment for prolonged periods of time," she said.
According to Dr. Thom, the surfaces most often touched by healthcare workers (supply carts, infusion pumps, and ventilators) are the most commonly contaminated, suggesting "a potential for transmission from one patient to another via the hands of healthcare workers," she said.
"These results provide more evidence of the need to achieve 100% compliance with hand hygiene, and suggest that more emphasis should be placed on routine cleaning and disinfection of environmental surfaces," she added.
L. Silvia Munoz-Price, MD, from the Division of Infectious Diseases at the University of Miami Miller School of Medicine in Florida, noted that these findings confirm that environmental surfaces in the proximity of patients infected with A?baumannii do, in fact, become contaminated with this organism.
According to Dr. Munoz-Price, the results of this study should be used to inform environmental personnel and healthcare workers about the importance of thoroughly cleaning and complying with hand hygiene, respectively.
"Environmental surfaces close to patients infected or colonized with A?baumannii should be cleaned extensively on a daily basis in order to decrease the possibility of horizontal transmission," she asserted.
The study received grant support from the National Institutes of Health. Dr. Thom and Dr. Munoz-Price have disclosed no relevant financial relationships.
Fifth Decennial International Conference on Healthcare-Associated Infections (ICHAI) 2010: Abstract?673. Presented March?20, 2010.
