Masks and face coverings for the lay public: A narrative update
Masks and face coverings for the lay public: A narrative update
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DOI：
10.31235/osf.io/wuk6a
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发表时间：
2020-10
期刊：
影响因子：
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通讯作者：
T. Czypionka;T. Greenhalgh;M. Schmid;D. Bassler
中科院分区：
文献类型：
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作者：
T. Czypionka;T. Greenhalgh;M. Schmid;D. Bassler
是否以及何时要求普通公众戴口罩或面罩以防止Covid-19传播的问题仍然存在争议。在过去的六个月里，已经积累了大量的研究文献，涵盖了一系列学科。我们总结了这些文献，这些文献（虽然没有被普遍接受）一致地指出了一些重要的结论。首先，越来越多的证据表明，SARS-CoV-2病毒可以通过空气传播，因此可能会远距离传播并被吸入。因此，感染控制政策必须超越洗手和清洁表面等“接触和飞沫”措施。其次，如果广泛佩戴口罩和面罩，似乎可以显著减少病毒的人群传播。第三，关于人群掩蔽对Covid-19的预防作用的随机对照试验仍然很少，尚未解决源头控制问题。第四，戴口罩的危害似乎相对较小（尽管绝非微不足道），在大流行的最初几个月被高估了；当COVID-19在人群中传播时，弊大于利。第五，面罩、带阀呼吸器和易碎或不合适的面罩不适合源头控制。最后，强制性掩蔽涉及与个人自由的权衡，因此只有在威胁严重且无法通过侵入性较低的手段获得好处时，才应奉行此类政策。
The question of whether and when to mandate the wearing of masks or face coverings by the lay public to prevent the spread of Covid-19 remains controversial. A vast research literature, across a range of academic disciplines, has accumulated in the past six months. We summarise that literature, which (whilst not universally accepted) points consistently to some important conclusions. First, there is growing evidence that the SARS-CoV-2 virus is airborne and hence may spread long distances and be inhaled. Infection control policy must therefore go beyond ‘contact and droplet’ measures such as hand-washing and cleaning surfaces. Second, masks and face coverings, if widely worn, appear to significantly reduce population transmission of the virus. Third, randomized controlled trials of the preventive impact of population masking in Covid-19 remain sparse and have yet to address the question of source control. Fourth, the harms of wearing masks appear to be relatively minor (though by no means trivial) and were over-estimated in the early months of the pandemic; harms are outweighed by benefits when COVID-19 is spreading in a population. Fifth, face shields, valved respirators and flimsy or ill-fitting face coverings are unsuitable for source control. Finally, mandated masking involves a trade-off with personal freedom so such policies should be pursued only if the threat is severe and the benefits cannot be achieved through less intrusive means.