Epidemiological Benchmarks of the COVID-19 Outbreak Control in China After Wuhan's Lockdown: A Modelling Study with an Empirical Approach
23 Pages Posted: 28 Feb 2020More...
Background: In response to the coronavirus disease 2019 (COVID-19) epidemic, the central government of China imposed a lockdown in the epicentre, Wuhan city of Hubei province. Timely assessment of the epidemic situations in Hubei, as well as other provinces, is urgently needed.
Methods: We developed an empirical model based on a Bass-Susceptible-Infected-Recovered model to capture the COVID-19 epidemics in Chinese provinces and cities after Wuhan’s lockdown on 23rd January. Our model identified the province-specific transmission parameters, exogenous forces of infection, and effective population sizes using reported time-series between 24th January to 12th February. The model characterised the basic reproduction numbers and the trends of effective reproduction numbers. We forecasted future trends of COVID-19 under several policy scenarios immediately after 12th February.
Findings: The estimators of the basic reproduction numbers of COVID-19 after the lockdown of Wuhan ranged from 1·66 (95% Credible interval (CrI): 0·72, 2·87) in Fujian to 5·51 (95% CrI: 3·87-6·85) in Jilin. Most provinces had effective reproduction numbers close to one by 12th February, while the numbers in Hubei, Heilongjiang, and Guizhou remained around two. The exogenous force of infection already existed in other provinces even after Wuhan’s lockdown, for example, 31% (95% CrI: 12%-55%) of total infection burden in Fujian and 19% (95% CrI: 5%-44%) in Shanghai on 12th February. However, the number of active cases in half of the provinces will not be modified significantly (<10%) after excluding all future exogenous impacts. Despite the projected decline of active cases after mid-February, lifting the current stringent control measures on 24th February would result in a second wave of epidemic.
Interpretation: Although the epidemic of COVID-19 in China started to decelerate from mid-February, maintaining the current declines remains a challenge, especially when strict social distancing ends.
Funding Statement: The authors stated: "None declared."
Declaration of Interests: The authors declare that they have no competing interests.
Keywords: Coronavirus disease 2019; COVID-19; outbreak analysis; effective reproduction number; lockdown; Bass-SIR model; mathematical model
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