Modeling the Epidemic Dynamics and Control of COVID-19 Outbreak in China

Zhao, Shilei; Chen, Hua

The coronavirus disease 2019 (COVID-19) is rapidly spreading over China and more than 30 countries in last two months. COVID-19 has multiple characteristics distinct from other infectious diseases, including a high infectivity during incubation, time delay between real dynamics and daily observed case numbers, and the effects from multiple quarantine and control measures. We develop a model SUQC to adequately characterizes the dynamics of COVID-19 and explicitly model the control by artificial measures, which is more suitable for analysis than other existing epidemic models. The SUQC model is applied to the daily released data of the confirmed infected to analyze the outbreak of COVID-19 in Wuhan, Hubei (excluding Wuhan), China (excluding Hubei) and four first-tier cities of China. We find that, before January 30, 2020, all these regions except Beijing have a reproductive number R>1, and after January 30, all regions have a reproductive number R<1, indicating the effectiveness of the quarantine and control measures in inhibiting COVID-19. The confirmation rate of Wuhan is 0.0643, significantly lower than 0.1914 of Hubei (excluding Wuhan) and 0.2189 of China (excluding Hubei), but increases to 0.3229 after Feb 12th when clinical diagnosis was adopted. The un-quarantined infected individuals in Wuhan on February 12, 2020 is as high as 3,509 and decreases to 334 on February 21th, 2020. After fitting the model with recent data, we predict that the end times of COVID-19 of Wuhan and Hubei are around late-March, of China (excluding Hubei) around mid-March, and of the four tier-one cities before March 2020. A total of 80,511 individuals of the whole country are infected, among which 49,510 are from Wuhan, 17,679 from Hubei(excluding Wuhan), and the rest 13,322 from other regions of China (excluding Hubei). We suggest the rigorous quarantine and control measures should be kept before March in Beijing, Shanghai, Guangzhou and Shenzhen, and before late-March in Hubei. The model can also be useful to predict the trend of epidemic and provide quantitative guide for other counties in a high risk of outbreak, such as South Korea, Japan and Iran.