Abstract
Backgrounds There has been a novel coronavirus (2019-nCoV) pneumonia outbreak in China since December 2019, and which spreads internationally. This is the first study to quantify the basic reproduction number, R0, of 2019-nCoV in the early phase of the outbreak.
Methods Accounting for the impact of the variations in disease reporting rate, we modelled the epidemic curve of 2019-nCoV cases time series, in mainland China from January 10 to January 21, 2020, through the exponential growth. With the estimated intrinsic growth rate (γ), we estimated R0 by using the serial intervals (SI) of two other well-known coronavirus diseases, MERS and SARS, as approximations for the true unknown SI.
Findings The early outbreak data largely follows the exponential growth. We estimated that the mean R0 ranges from 3.30 (95%CI: 2.73-3.96) to 5.47 (95%CI: 4.16-7.10) associated with 0-fold to 2-fold increase in the reporting rate. With rising report rate, the mean R0 is likely to be below 5 but above 3.
Conclusion The mean estimate of R0 for the 2019-nCoV ranges from 3.30 (95%CI: 2.73-3.96) to 5.47 (95%CI: 4.16-7.10), and significantly larger than 1. Our findings indicate the potential of 2019-nCoV to cause outbreaks.
Footnotes
Email address of all authors SZ: zhaoshi.cmsa{at}gmail.com, JR: jimran{at}connect.hku.hk, SSM: salihu-sabiu.musa{at}connect.polyu.hk, GY: kennethgpy{at}link.cuhk.edu.hk, DG: dzgao{at}shnu.edu.cn, YL: yijun.lou{at}polyu.edu.hk, LY: l.yang{at}polyu.edu.hk, DH: daihai.he{at}polyu.edu.hk