Inference of start time of resurgent COVID-19 epidemic in Beijing with SEIR dynamics model and evaluation of control measure effect
10.3760/cma.j.cn112338-20200706-00927
- VernacularTitle:SEIR动力学模型辅助北京市新发地新型冠状病毒肺炎疫情传播起始时间溯源和防控效果评价
- Author:
Yongyue WEI
1
;
Jinxing GUAN
;
Yang ZHAO
;
Sipeng SHEN
;
Feng CHEN
Author Information
1. 南京医科大学公共卫生学院，全球健康中心 211166
- Keywords:
COVID-19;
Transmission dynamics model;
Epidemic tracing
- From:
Chinese Journal of Epidemiology
2020;41(11):1772-1776
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To infer the start time of the resurgent COVID-19 epidemic in Xinfadi wholesale market in Beijing in June 2020 and evaluate the effect of comprehensive prevention and control measures in this epidemic.Methods:SEIR dynamics model was used to fit daily onset infections to search the start date of this resurgent COVID-19 epidemic in Beijing. The number of cumulative infections from June 12 to July 1 in Beijing were fitted considering different levels of control strength.Results:The current reemerged COVID-19 epidemic in Beijing probably started between May 22 and May 28 (cumulative probability: 95 %), with the highest probability on May 25 (23 %). The R0 of the current reemerged COVID-19 epidemic was 4.22 (95 %CI: 2.88-7.02). Dynamic model fitting suggested that by June 11, the cumulative number of COVID-19 cases would reached 99 (95 %CI: 77-121), which was in line with the actual situation, and without control, by July 1, the cumulative number of COVID-19 cases would reach 65 090 (95 %CI: 39 068-105 037). Since June 12, comprehensive prevention and control measures have been implemented in Beijing, as of July 1, compared with uncontrolled situation, the number of infections had been reduced by 99 %, similar to the fitting result of a 95 % reduction of the transmission rate. The sensitivity analysis showed consistent results. Conclusions:For the emergent outbreak of COVID-19, the dynamics model can be used to infer the start time of the transmission and help tracing the source of epidemic. The comprehensive prevention and control measures taken in Beijing have quickly blocked over 95 % of the transmission routes and reduced 99 % of the infections, containing the sudden epidemic timely and effectively, which have value in guiding the prevention and control of the epidemic in the future.
