Objective  To quantitatively evaluate the effectiveness of closed-loop management in the control of COVID-19 during Beijing Winter Olympics and Paralympics Games in 2022.

  Methods  The information about COVID-19 prevention and control during Beijing Winter Olympics and Paralympics Games from January 4 to March 13, 2022, such as the airport arrivals and confirmed positive cases, were collected. According to the non-closed-loop management (regular epidemic prevention and control measure), a population transmission dynamic model was built to simulate daily new infections, daily detection rate and cumulative detection rate, and the results were compared with the actual data to evaluate the effectiveness of the closed-loop management.

  Results  The results of the model suggested that if regular management were adopted, the daily number of new infections during Beijing Winter Olympics and Paralympic would reach the peak on February 12 (120), 10 days later than the actual peak and an increase of 94 cases. Compared with regular management, closed-loop management might prevent 95.24% of infections (3,763 vs. 179); The cumulative detection rate of regular management was 21.02 times higher than that of closed-loop management (0.15% vs. 0.07‰). During this period, the cumulative detection rates of actual airport inbound athletes, team officials and other stakeholders were similar (1.68% vs. 1.76%). In the closed loop, the cumulative detection rate of both groups decreased (0.49‰ vs. 0.05‰), and the daily detection rate of athletes and team officials was much higher than that of other stakeholders (the highest daily detection rate: 3.15‰ vs. 0.22‰).

  Conclusion  The closed-loop management during Beijing Winter Olympics and Paralympics Games could detect the infections early and effectively reduce the number of infections, providing a reference for developing epidemic prevention and control strategies for future large-scale sports events.