Queensland University of Technology (QUT), Science and Engineering Faculty, School of Earth and Atmospheric Sciences, Brisbane, Australia.
Queensland University of Technology, Faculty of Health, School of Biomedical Sciences, Brisbane, Australia.
Environ Pollut. 2021 May 1;276:115767. doi: 10.1016/j.envpol.2020.115767. Epub 2020 Nov 6.
Whether virulent human pathogenic coronaviruses (SARS-CoV, MERS-CoV, SARS-CoV-2) are effectively transmitted by aerosols remains contentious. Transmission modes of the novel coronavirus have become a hot topic of research with the importance of airborne transmission controversial due to the many factors that can influence virus transmission. Airborne transmission is an accepted potential route for the spread of some viral infections (measles, chickenpox); however, aerosol features and infectious inoculum vary from one respiratory virus to another. Infectious virus-laden aerosols can be produced by natural human respiratory activities, and their features are vital determinants for virus carriage and transmission. Physicochemical characteristics of infectious respiratory aerosols can influence the efficiency of virus transmission by droplets. This critical review identifies studies reporting instances of infected patients producing airborne human pathogenic coronaviruses, and evidence for the role of physical/chemical characteristics of human-generated droplets in altering embedded viruses' viability. We also review studies evaluating these viruses in the air, field studies and available evidence about seasonality patterns. Ultimately the literature suggests that a proportion of virulent human coronaviruses can plausibly be transmitted via the air, even though this might vary in different conditions. Evidence exists for respirable-sized airborne droplet nuclei containing viral RNA, although this does not necessarily imply that the virus is transmittable, capable of replicating in a recipient host, or that inoculum is sufficient to initiate infection. However, evidence suggests that coronaviruses can survive in simulated droplet nuclei for a significant time (>24 h). Nevertheless, laboratory nebulized virus-laden aerosols might not accurately model the complexity of human carrier aerosols in studying airborne viral transport. In summary, there is disagreement on whether wild coronaviruses can be transmitted via an airborne path and display seasonal patterns. Further studies are therefore required to provide supporting evidence for the role of airborne transmission and assumed mechanisms underlying seasonality.
高致病性人类冠状病毒（SARS-CoV、MERS-CoV、SARS-CoV-2）是否能通过气溶胶有效传播仍存在争议。由于许多因素可能影响病毒的传播，新型冠状病毒的传播方式已成为研究的热点。空气传播是某些病毒感染（麻疹、水痘）传播的公认潜在途径；然而，气溶胶特征和感染性接种量因呼吸道病毒而异。感染病毒的载气气溶胶可由人体自然呼吸活动产生，其特征是病毒携带和传播的重要决定因素。传染性呼吸道气溶胶的理化特性可影响飞沫传播的效率。本综述确定了报告感染患者产生载有人致病性冠状病毒的空气传播的研究，并提供了证据证明人体产生的飞沫的理化特性在改变嵌入病毒的存活能力方面的作用。我们还回顾了评估这些病毒在空气中、现场研究以及有关季节性模式的现有证据的研究。最终，文献表明，一些高致病性人类冠状病毒可能通过空气传播，尽管在不同条件下可能有所不同。虽然这并不一定意味着病毒具有传染性、能够在受感染的宿主中复制，或者接种足够引发感染，但存在含有病毒 RNA 的可吸入大小的空气传播飞沫核的证据。然而，证据表明冠状病毒可以在模拟的飞沫核中存活很长时间（超过 24 小时）。然而，在研究空气传播病毒传输时，实验室雾化病毒载气气溶胶可能无法准确模拟人类携带者气溶胶的复杂性。总之，关于野生冠状病毒是否可以通过空气传播途径传播以及是否存在季节性模式存在分歧。因此，需要进一步的研究为空气传播的作用和假设的季节性机制提供支持证据。
