Abstract
In January 2020, a COVID-19 outbreak was detected in Sichuan Province of China. The aim of this work is to characterize the epidemiology of the Sichuan outbreak and estimate the impact of the performed interventions. We analyzed patient records for all laboratory-confirmed cases reported in the province for the period of January 21 to March 16, 2020. To estimate the basic and daily reproduction numbers, we used a Bayesian framework. In addition, we estimate the number of cases averted by the implemented control strategies. The outbreak resulted in 539 confirmed cases, lasted less than two months, and no further local transmission was detected after February 27. The median age of local cases was 8 years older than that of imported cases. Severity of symptoms increased with age. We estimated R0 at 2.4 (95% CI: 1.6–3.7). The epidemic was self-sustained for about 3 weeks before going below the epidemic threshold 3 days after the declaration of a public health emergency by Sichuan authorities. Our findings indicate that, were the control measures be adopted four weeks later, the epidemic could have lasted 49 days longer (95%CI: 31-68 days), causing 9,216 (95%CI: 1,317-25,545) more cases and possibly overwhelming Sichuan healthcare system.
Competing Interest Statement
The authors have declared no competing interest.
Funding Statement
The authors thank the West China Biomedical Big Data Center providing the data and the access to the platform for simulations and Nicole Samay for her assistance in preparing the figures.This work was supported by the Special Funds for Prevention and Control of COVID-19 of Sichuan University (0082604151026), Chengdu Science and Technology Bureau (2020-YF05-00073-SN), the Fundamental Research Funds for the Central Universities (1082204112289), the Science and Technology Department of Sichuan Province (2020YFS0007, 2020YFS0009), and the National Natural Science Foundation of China (11975071, 61673085).
Author Declarations
I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.
Yes
The details of the IRB/oversight body that provided approval or exemption for the research described are given below:
The study was approved by the Clinical Trials and Biomedical Ethics Committee of West China Hospital, Sichuan University (No. 2020190).
All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.
Yes
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Data Availability
Data and code will be made available on Figshare upon acceptance of the manuscript.