Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Nagoya, 466-8555, Japan; Center of Biomedical Physics and Information Technology, Nagoya Institute of Technology, Nagoya, 466-8555, Japan.
Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Nagoya, 466-8555, Japan.
Comput Biol Med. 2022 Jul;146:105548. doi: 10.1016/j.compbiomed.2022.105548. Epub 2022 Apr 26.
In the summer of 2021, the Olympic Games were held in Tokyo during the state of emergency due to the spread of COVID-19 pandemic. New daily positive cases (DPC) increased before the Olympic Games, and then decreased a few weeks after the Games. However, several cofactors influencing DPC exist; consequently, careful consideration is needed for future international events during an epidemic.
The impact of the Olympic Games on new DPC were evaluated in the Tokyo, Osaka, and Aichi Prefectures using a well-trained and -evaluated long short-term memory (LSTM) network. In addition, we proposed a compensation method based on effective reproduction number (ERN) to assess the effect of the national holidays on the DPC.
During the spread phase, the estimated DPC with LSTM was 30%-60% lower than that of the observed value, but was consistent with the compensated value of the ERN for the three prefectures. During the decay phase, the estimated DPC was consistent with the observed values. The timing of the decay coincided with achievement of a fully-vaccinated rate of 10%-15% of people aged <65 years.
The up- and downsurge of the pandemic wave observed in July and September are likely attributable to high ERN during national holiday periods and to the vaccination effect, especially for people aged <65 years. The effect of national holidays in Tokyo was rather notable in Aichi and Osaka, which are distant from Tokyo. The effect of the Olympic Games on the spread and decay of the pandemic wave is neither dominant nor negligible due to the shifting of the national holiday dates to coincide with the Olympic Games.
2021 年夏季，由于 COVID-19 大流行，奥运会在东京举行。在奥运会之前，新的每日阳性病例（DPC）增加，然后在奥运会后几周减少。然而，影响 DPC 的因素有很多；因此，在未来的疫情期间，需要仔细考虑国际赛事。
利用经过良好训练和评估的长短期记忆（LSTM）网络，在东京、大阪和爱知县评估奥运会对新 DPC 的影响。此外，我们提出了一种基于有效繁殖数（ERN）的补偿方法，以评估国定假日对 DPC 的影响。
在传播阶段，LSTM 估计的 DPC 比观察值低 30%-60%，但与三个县的 ERN 补偿值一致。在衰减阶段，估计的 DPC 与观察值一致。衰减的时间与 65 岁以下人群完全接种率达到 10%-15%的时间一致。
7 月和 9 月观察到的疫情波峰和波谷可能是由于国定假日期间 ERN 较高以及疫苗接种效果，特别是对 65 岁以下人群的影响。东京的国定假日对距离较远的爱知和大阪的影响相当显著。由于国定假日的日期与奥运会相吻合，奥运会对疫情波的传播和衰减的影响既不占主导地位，也不可忽视。
