JDR Vol.16 No.1 pp. 6-11
doi: 10.20965/jdr.2021.p0006


COVID-19 Outbreak Forecasting and Effects of Self-Restraint Against Excursions in Tokyo, Japan, as of the End of March, 2020, Before the Emergency Declaration on April 7, 2020

Yoshiyuki Sugishita*,†, Junko Kurita**, Tamie Sugawara*, and Yasushi Ohkusa*

*National Institute of Infectious Diseases (NIID)
1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan

Corresponding author

**Department of Nursing, Tokiwa University, Ibaraki, Japan

September 17, 2020
October 26, 2020
January 30, 2021
coronavirus disease 2019, intensive care unit (ICU) beds, susceptible–infected–recovered (SIR) model, exhaustion of medical resources, post evaluation for forecast

In Tokyo, Japan, coronavirus disease 2019 (COVID-19) cases have been increasing gradually since late March 2020. This study was aimed to predict the effects of self-restraint against excursions in Tokyo before the emergency declaration of April 7, 2020. Data of symptomatic patients collected between January 14 and March 28, 2020, in Tokyo, were used to formulate a susceptible–infected–recovered (SIR) model using three age classes and estimate the basic reproduction number (R0). Based on the estimated R0, we inferred outbreak outcomes and medical burdens if self-restraint against excursions had not been enacted. Thereafter, we estimated the effects of self-restraint against excursions. The results suggested an R0 value of 2.86, with a 95% confidence interval of 2.73–2.97. It is likely that the exhaustion of medical resources could have occurred on April 28, 2020, if no self-restraint against excursions had occurred. If self-restraint against excursions had been enacted from April 6, 2020, and more than 60% of trips outside the home had been restricted voluntarily, medical care services would then have been predicted to be maintained. Our suggestion might have contributed to countermeasures against COVID-19 in Tokyo.

Cite this article as:
Yoshiyuki Sugishita, Junko Kurita, Tamie Sugawara, and Yasushi Ohkusa, “COVID-19 Outbreak Forecasting and Effects of Self-Restraint Against Excursions in Tokyo, Japan, as of the End of March, 2020, Before the Emergency Declaration on April 7, 2020,” J. Disaster Res., Vol.16, No.1, pp. 6-11, 2021.
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Last updated on Mar. 05, 2021