La Fauci V, Costa G B, Facciolà A, Conti A, Riso R, Squeri R
Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Italy.
Postgraduate Medical School in Hygiene and Preventive Medicine, University of Messina, Italy.
J Prev Med Hyg. 2017 Jun;58(2):E161-E165.
Nosocomial pneumonia accounts for the vast majority of healthcare-associated infections (HAI). Although numerous medical devices have been discussed as potential vehicles for microorganisms, very little is known about the role played by oxygen humidifiers as potential sources of nosocomial pathogens. The purpose of this research was to evaluate the safety of the reuse of humidifiers by analysing the rate of microbial contamination in reusable and disposable oxygen humidifiers used during therapy, and then discuss their potential role in the transmission of respiratory pathogens.
Water samples from reusable and disposable oxygen humidifiers were collected from different wards of the University Hospital of Messina, Italy, where nosocomial pneumonia has a higher incidence rate due to the "critical" clinical conditions of inpatients. In particular, we monitored the Internal Medicine and Pulmonology wards for the medical area; the General Surgery and Thoracic and Cardiovascular Surgery wards for the surgical area and the Intensive Care Unit and Neonatal Intensive Care Unit for the emergency area. The samples were always collected after a period of 5 days from initial use for both types of humidifiers. Samples were processed using standard bacteriological techniques and microbial colonies were identified using manual and automated methods.
High rates of microbial contamination were observed in samples from reusable oxygen humidifiers employed in medical (83%), surgical (77%) and emergency (50%) areas. The most relevant pathogens were Pseudomonas aeruginosa, amongst the Gram-negative bacteria, and Staphylococcus aureus, amongst the Gram-positive bacteria. Other pathogens were detected in lower percentage. The disposable oxygen humidifier samples showed no contamination.
This research presents evidence of the high rate and type of microbial contamination of reusable humidifiers employed for oxygen therapy. These devices may thus be involved in the transmission of potential pathogens. It could be important, for the prevention of nosocomial pneumonia, to replace them with singleuse humidifiers for which the absence of microbial contamination has been confirmed.
医院获得性肺炎占医疗相关感染（HAI）的绝大多数。尽管众多医疗设备被认为是微生物的潜在传播媒介，但对于氧气加湿器作为医院病原体潜在来源所起的作用却知之甚少。本研究的目的是通过分析治疗期间使用的可重复使用和一次性氧气加湿器中的微生物污染率，评估加湿器重复使用的安全性，然后讨论它们在呼吸道病原体传播中的潜在作用。
从意大利墨西拿大学医院的不同病房收集可重复使用和一次性氧气加湿器的水样，该医院因住院患者的“危急”临床状况，医院获得性肺炎发病率较高。具体而言，我们监测了医疗区域的内科和肺病科病房；外科区域的普通外科、胸心血管外科病房以及急诊区域的重症监护病房和新生儿重症监护病房。两种类型的加湿器均在初次使用5天后采集样本。样本采用标准细菌学技术处理，微生物菌落通过手动和自动方法进行鉴定。
在医疗（83%）、外科（77%）和急诊（50%）区域使用的可重复使用氧气加湿器样本中观察到高微生物污染率。最主要的病原体是革兰氏阴性菌中的铜绿假单胞菌和革兰氏阳性菌中的金黄色葡萄球菌。其他病原体的检出率较低。一次性氧气加湿器样本未显示污染。
本研究提供了用于氧气治疗的可重复使用加湿器微生物污染的高发生率和类型的证据。因此，这些设备可能参与了潜在病原体的传播。为预防医院获得性肺炎，用已证实无微生物污染的一次性加湿器取代它们可能很重要。
