Pulmonary Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
Lancet Respir Med. 2020 Sep;8(9):914-924. doi: 10.1016/S2213-2600(20)30323-4. Epub 2020 Jul 24.
The global pandemic of COVID-19 has been associated with infections and deaths among health-care workers. This Viewpoint of infectious aerosols is intended to inform appropriate infection control measures to protect health-care workers. Studies of cough aerosols and of exhaled breath from patients with various respiratory infections have shown striking similarities in aerosol size distributions, with a predominance of pathogens in small particles (<5 μm). These are immediately respirable, suggesting the need for personal respiratory protection (respirators) for individuals in close proximity to patients with potentially virulent pathogens. There is no evidence that some pathogens are carried only in large droplets. Surgical masks might offer some respiratory protection from inhalation of infectious aerosols, but not as much as respirators. However, surgical masks worn by patients reduce exposures to infectious aerosols to health-care workers and other individuals. The variability of infectious aerosol production, with some so-called super-emitters producing much higher amounts of infectious aerosol than most, might help to explain the epidemiology of super-spreading. Airborne infection control measures are indicated for potentially lethal respiratory pathogens such as severe acute respiratory syndrome coronavirus 2.
COVID-19 全球大流行与医护人员的感染和死亡有关。本观点主要针对传染性气溶胶进行探讨，旨在为医护人员提供适当的感染控制措施。对咳嗽气溶胶和不同呼吸道感染患者呼出的气体进行的研究表明，气溶胶粒径分布具有明显的相似性，病原体主要存在于小颗粒（<5μm）中。这些颗粒可以立即被吸入，这表明与具有潜在毒性病原体的患者近距离接触的个体需要进行个人呼吸防护（呼吸器）。目前没有证据表明某些病原体仅存在于大飞沫中。外科口罩可能会为吸入传染性气溶胶提供一定程度的呼吸防护，但不如呼吸器有效。然而，患者佩戴的外科口罩可减少传染性气溶胶对医护人员和其他个体的暴露。一些所谓的超级传播者产生的传染性气溶胶比大多数人多得多，这种传染性气溶胶产生的变异性可能有助于解释超级传播的流行病学。对于严重急性呼吸综合征冠状病毒 2 等具有潜在致命性的呼吸道病原体，需要采取空气传播感染控制措施。
