Not all fun and games: Potential incidence of SARS-CoV-2 infections during the Tokyo 2020 Olympic Games
Not all fun and games: Potential incidence of SARS-CoV-2 infections during the Tokyo 2020 Olympic Games
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DOI：
10.3934/mbe.2021474
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发表时间：
2021-01-01
影响因子：
2.6
通讯作者：
Nishiura, Hiroshi
中科院分区：
文献类型：
--
作者：
Linton, Natalie M.;Jung, Sung-mok;Nishiura, Hiroshi
2020年东京奥运会和残奥会是自2019冠状病毒病（COVID-19）大流行开始以来举办的最多样化的国际大规模聚会活动。重新安排的奥运会将推迟到2021年夏季举行，届时主办城市东京的COVID-19传播水平将达到有史以来最高水平。与此同时，由于占主导地位的病毒株和日本尚未超过15%的人口完全接种COVID-19疫苗，令人担忧的德尔塔病毒变体正在获得关注。为了量化奥运会期间可能出现的继发性病例的潜在数量，我们使用多类型分支过程模型进行了场景分析。我们考虑了奥运会认证个人、东京普通民众和国内观众对传播的不同贡献。在这样做的过程中，我们展示了传播如何随着时间的推移在这些不同的群体中演变，提醒人们不要放松感染预防方案，并支持禁止所有观众的决定。如果预防措施得到很好的实施，我们估计，到奥运会结束时，奥运会认证个人中的新病例数量将接近于零。然而，如果传播不受控制，我们的模型表明，数百名奥运会认证个人将被感染，东京的日发病率将达到4,000例以上。如果允许国内观众观看（场馆容量为50%），我们估计可能有250多名观众被感染到达东京场馆，可能在东京/奥运会期间产生300多名额外的二次感染。我们还发现，在奥运会期间直接归因于假定暴露的感染病例数对当地的流行病动态高度敏感。因此，有必要采取公共卫生措施，将传播水平降低并维持在流行病水平以下，以防止跨群体传播。
The Tokyo 2020 Olympic and Paralympic Games represent the most diverse international mass gathering event held since the start of the coronavirus disease 2019 (COVID-19) pandemic. Postponed to summer 2021, the rescheduled Games were set to be held amidst what would become the highest-ever levels of COVID-19 transmission in the host city of Tokyo. At the same time, the Delta variant of concern was gaining traction as the dominant viral strain and Japan had yet to exceed fifteen percent of its population fully vaccinated against COVID-19. To quantify the potential number of secondary cases that might arise during the Olympic Games, we performed a scenario analysis using a multitype branching process model. We considered the different contributions to transmission of Games accredited individuals, the general Tokyo population, and domestic spectators. In doing so, we demonstrate how transmission might evolve in these different groups over time, cautioning against any loosening of infection prevention protocols and supporting the decision to ban all spectators. If prevention measures were well observed, we estimated that the number of new cases among Games accredited individuals would approach zero by the end of the Games. However, if transmission was not controlled our model indicated hundreds of Games accredited individuals would become infected and daily incidence in Tokyo would reach upwards of 4,000 cases. Had domestic spectators been allowed (at 50% venue capacity), we estimated that over 250 spectators might have arrived infected to Tokyo venues, potentially generating more than 300 additional secondary infections while in Tokyo/at the Games. We also found the number of cases with infection directly attributable to hypothetical exposure during the Games was highly sensitive to the local epidemic dynamics. Therefore, reducing and maintaining transmission levels below epidemic levels using public health measures would be necessary to prevent cross-group transmission.