How does the outbreak of 2019-nCoV spread in mainland China? A retrospective analysis of the dynamic transmission routes

Xiandeng Jiang; Le Chang; Yanlin Shi

is the (which was not peer-reviewed) The copyright holder for this preprint . https://doi.org/10.1101/2020.03.01.20029645 doi: medRxiv preprint (big to small). There were a few additional detected such transmissions on the second day, including those from Hubei to Guangxi, from Zhejiang to Fujian, and from Guangdong to Yunnan, Hunan and Fujian. The number of such identified inter-province routes, however, reduced rapidly over the next three days. On the fifth day (February 4), no influential transmission routes were found from Hubei to directly affect other provinces, and there were only three influential routes identified nationally, including Zhejiang-Shaanxi, Zhejiang-Jiangxi and Jiangxi-Shanghai. The number of those detected inter-province routes declined again in the next few days, and on day 13, only Henan-Heilongjiang was found influential. On days 19 and 20 (February 18 and 19) , there were no influential inter-province transmissions identified. The above findings suggest that the number of influential inter-province transmissions overall dropped quickly in the first five days and then reduced steadily for the rest fifteen days. This is consistent with the observations of Figure 3 On each day, we report the mean, standard deviation (Std. Dev.), the 25% quantile (Q 1 ) and 75% quantile (Q 3 ) of those estimates in Table 1 , which also leads to consistent findings.