Basic reproduction number of 2019 Novel Coronavirus Disease in Major Endemic Areas of China: A latent profile analysis

Objective The aim of the study is to analyze the latent class of basic reproduction number (R 0 ) trend of 2019 novel coronavirus disease (COVID-19) in major endemic areas of China. Methods The provinces that reported more than 500 cases of COVID-19 till February 18, 2020 were selected as the major endemic area. The Verhulst model was used to fit the growth rate of cumulative confirmed cases. The R 0 of COVID-19 was calculated using the parameters of severe acute respiratory syndrome (SARS) and COVID-19, respectively. The latent class of R 0 was analyzed using a latent profile analysis model. Results The median R 0 calculated from SARS and COVID-19 parameters were 1.84 - 3.18 and 1.74 - 2.91, respectively. The R 0 calculated from the SARS parameters was greater than that of calculated from the COVID-19 parameters ( Z = −4.782 - −4.623, P < 0.01). Both R 0 can be divided into three latent classes. The initial value of R 0 in class 1 (Shandong Province, Sichuan Province and Chongqing Municipality) was relatively low and decreases slowly. The initial value of R 0 in class 2 (Anhui Province, Hunan Province, Jiangxi Province, Henan Province, Zhejiang Province, Guangdong Province and Jiangsu Province) was relatively high and decreases rapidly. Moreover, the initial value of R 0 of class 3 (Hubei Province) was between that of class 1 and class 2, but the higher level of R 0 lasts longer and decreases slowly. Conclusion The results indicated that overall trend of R 0 has been falling with the strengthening of China’s comprehensive prevention and control measures for COVID-19, however, presents regional differences.