Estimation of the epidemic properties of the 2019 novel coronavirus: A mathematical modeling study

Jinghua Li; Yijing Wang; Stuart Gilmour; Mengying Wang; Daisuke Yoneoka; Ying Wang; Xinyi You; Jing Gu; Chun Hao; Liping Peng; Zhicheng Du; Dong Roman Xu; Yuantao Hao

In the beginning stages of an epidemic, mathematical modeling is essential to understand the dynamics of the new disease, and to assess the organism's infectiousness and rapidity of spread. This is primarily achieved by calculation of the basic reproduction number, denoted as " , which measures the number of secondary cases that can be expected to be generated from a single case of the disease. 6 Initial research from the first weeks of the COVID-19 outbreak estimated the basic reproduction number to be between 2.20 and 3.58, indicating large uncertainty in estimates of its infectiousness. 7, 8 Other unpublished estimates also placed the value of " within this range, 9 with wide uncertainty. 5 All of these estimates of the basic reproduction number were based on data to the end of January, and did not use a long series of data from the period after the closure of Wuhan city. The data series for these reports also did not include significant periods of time after the Chinese New Year (24 th January, 2020), when a large number of people return to their home towns from large cities, with the attendant risk of significant spread of the disease. Wuhan city has a population of 11 million people 10 , but during the Chinese New Year as many as 5 million residents leave the city, and 70% of those who leave travel within Hubei province 11 , with the risk of significant spread of the disease within China, and especially across Hubei province, during the Chinese New Year period.