To mask or not to mask: Modeling the potential for face mask use by the general public to curtail the COVID-19 pandemic

Face mask use by the general public for limiting the spread of the COVID-19 pandemic is controversial, though increasingly recommended, and the potential of this intervention is not well understood. We develop a compartmental model for assessing the community-wide impact of mask use by the general, asymptomatic public, a portion of which may be asymptomatically infectious. Model simulations, using data relevant to COVID-19 dynamics in the US states of New York and Washington, suggest that broad adoption of even relatively ineffective face masks may meaningfully reduce community transmission of COVID-19 and decrease peak hospitalizations and deaths. Moreover, mask use decreases the effective transmission rate in nearly linear proportion to the product of mask effectiveness (as a fraction of potentially infectious contacts blocked) and coverage rate (as a fraction of the general population), while the impact on epidemiologic outcomes (death, hospitalizations) is highly nonlinear, indicating masks could synergize with other non-pharmaceutical measures. Notably, masks are found to be useful with respect to both preventing illness in healthy persons and preventing asymptomatic transmission. Hypothetical mask adoption scenarios, for Washington and New York state, suggest that immediate near universal (80%) adoption of moderately (50%) effective masks could prevent on the order of 17-45% of projected deaths over two months in New York, while decreasing the peak daily death rate by 34-58%, absent other changes in epidemic dynamics. Even very weak masks (20% effective) can still be useful if the underlying transmission rate is relatively low or decreasing: In Washington, where baseline transmission is much less intense, 80% adoption of such masks could reduce mortality by 24-65% (and peak deaths 15-69%), compared to 2-9% mortality reduction in New York (peak death reduction 9-18%). Our results suggest use of face masks by the general public is potentially of high value in curtailing community transmission and the burden of the pandemic. The community-wide benefits are likely to be greatest when face masks are used in conjunction with other non-pharmaceutical practices (such as social-distancing), and when adoption is nearly universal (nation-wide) and compliance is high. (c) 2020 The Authors. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

普通公众使用口罩以限制新冠疫情传播这一做法存在争议，尽管越来越受到推荐，但这种干预措施的潜力尚未得到充分理解。我们建立了一个分区模型，用于评估无症状的普通公众使用口罩对社区的影响，其中一部分人可能无症状但具有传染性。利用与美国纽约州和华盛顿州新冠疫情动态相关的数据进行的模型模拟表明，即使是广泛使用相对效果不佳的口罩，也可能显著减少新冠病毒在社区的传播，并降低住院高峰和死亡人数。此外，口罩的使用使有效传播率几乎与口罩有效性（作为潜在传染性接触被阻断的比例）和覆盖率（作为普通人口的比例）的乘积成线性比例下降，而对流行病学结果（死亡、住院）的影响则高度非线性，这表明口罩可以与其他非药物措施协同作用。值得注意的是，发现口罩在预防健康人患病和防止无症状传播方面都很有用。针对华盛顿州和纽约州的假设口罩使用情景表明，立即近乎普遍（80%）使用中等（50%）有效率的口罩，在纽约州两个月内可预防约17 - 45%的预计死亡人数，同时使每日最高死亡率降低34 - 58%，前提是疫情动态没有其他变化。即使是非常低效的口罩（20%有效），如果潜在传播率相对较低或正在下降，仍然可能有用：在华盛顿州，基线传播强度要低得多，80%的人使用这种口罩可使死亡率降低24 - 65%（最高死亡人数降低15 - 69%），相比之下，在纽约州死亡率仅降低2 - 9%（最高死亡人数降低9 - 18%）。我们的研究结果表明，普通公众使用口罩在遏制社区传播和减轻疫情负担方面可能具有很高的价值。当口罩与其他非药物措施（如社交距离）一起使用，且使用率近乎普遍（全国范围）且依从性较高时，对社区的益处可能最大。（c）2020作者。由爱思唯尔出版集团代表科爱传播有限公司制作和托管。这是一篇在CC BY许可（http://creativecommons.org/licenses/by/4.0/）下的开放获取文章。