[Application of mathematical models of infectious diseases in the evaluation of COVID-19 transmission risk at mass gatherings].

The SARS-CoV-2 Omicron variant is rampant in Europe and the United States, and the Delta variant has caused several small-scale outbreaks in China. It is particularly important to simulate the transmission risk of novel coronavirus pneumonia (COVID-19) during large-scale events, so as to ensure a good preparation of personnel, materials, isolation sites and other support work in advance. Taking the Beijing 2022 Winter Olympic Games as an example, this study introduces the use of mathematical models to simulate the entry risks, closed-loop risks and prevention and control measures of athletes, officials and other stakeholders of the Olympic Games. In the simulation results on January 19, 2022, the estimated number of Olympic Games-related infections who were identified at borders was 357 (95%CI: 153-568) and the observed number was 323. The estimated number of "seed" cases that entered the closed-loop of Olympics Games was 195 (95%CI: 43-335), and the observed number of cases in the closed-loop was 212. This study demonstrates the important role of mathematical models of infectious diseases in the pragmatic application of preventive medicine and public health.