Early epidemiological assessment of the transmission potential and virulence of 2019 Novel Coronavirus in Wuhan City: China, 2019-2020
Kenji Mizumoto, Katsushi Kagaya, Gerardo Chowell
doi: https://doi.org/10.1101/2020.02.12.20022434
Abstract
Background: Since the first cluster of cases was identified in Wuhan City, China, in December, 2019, 2019-nCoV has rapidly spread across China as well as caused multiple introductions in 25 countries as of February, 2020. Despite the scarcity of publicly available data, scientists around the world have made strides in estimating the magnitude of the epidemic, the basic reproduction number, and transmission patterns. Recently more evidence suggests that a substantial fraction of the infected individuals with the novel coronavirus show little if any symptoms, which suggest the need to reassess the transmission potential of emerging disease. The present study aimed to estimates of the transmissibility and virulence of 2019-nCov in Wuhan City, China, by reconstructing the underlying transmission dynamics. Methods: We employ statistical methods and publicly available epidemiological datasets to jointly derive estimates of transmissibility and severity associated with the novel coronavirus. For estimation, the daily series of laboratory-confirmed nCov cases and deaths in Wuhan City and epidemiological data of Japanese evacuees from Wuhan City on board government-chartered flights were used. Results: We found that our posterior estimates of basic reproduction number (R) in Wuhan City, China in 2019-2020 is calculated to be as high as 7.05 (95%CrI: 6.11-8.18) and the enhanced public health intervention after January 23rd in 2020 has declined R to 3.24 (95%CrI: 3.16-3.32), with the total number of infections (i.e. cumulative infections) estimated at 983006 (95%CrI: 759475-1296258) in Wuhan City, raising the proportion of infected individuals to 9.8% (95%CrI: 7.6-13.0%). We also found that most recent crude infection fatality ratio (IFR) and time-delay adjusted IFR is estimated to be 0.07% (95% CrI: 0.05%-0.09%) and 0.23% (95%CrI: 0.17-0.30%), which is several orders of magnitude smaller than the crude CFR at 4.06% Conclusions: We have estimated key epidemiological parameters of the transmissibility and virulence of 2019-nCov in Wuhan, China, 2019-2020 using an ecological modelling approach. The power of our approach lies in the ability to infer epidemiological parameters with quantified uncertainty from partial observations collected by surveillance systems.
*注，本文为预印本论文手稿，是未经同行评审的初步报告，其观点仅供科研同行交流，并不是结论性内容，请使用者谨慎使用.
