Early Transmission Dynamics in Wuhan, China, of Novel Coronavirus–Infected Pneumonia
Authors: Bo Yang
Ge Shao
Benjamin J Cowling
Qun Li
Guoqing Shi
Jessica Y Wong
Kathy S M Leung
Peng Wu
Yanping Zhang
Ruiqi Ren
Qi Wang
Jing Zhao
Dan Li
Huan Li
Chao Li
Xuhua Guan
Tian Liu
Zijian Feng
Qi Chen
Eric H Y Lau
Tommy T Y Lam
Joseph T Wu
Zhiqiang Deng
Boxi Liu
Gabriel M Leung
Suhua Zhou
Lei Zhou
Zhongfa Tao
Hui Liu
George F Gao
Yang Wu
Chuding Chen
Yeqing Tong
Rui Yang
Man Liu
Nijuan Xiang
Xiaoye Wang
Yang Yang
Wenxiao Tu
Yuan Liu
Lianmei Jin
Yinbo Luo
Rui Wang
Zhitao Ma
Xuesen Xing
Journal: New England Journal of Medicine (2020)
Discipline: CLINICAL MEDICINE
Keywords: novel coronavirus; 2019-nCoV; pneumonia; NCIP; Wuhan
Affiliations: From the Chinese Center for Disease Control and Prevention, Beijing (Q.L., X.W., L.Z., R.R., N.X., C.L., D.L., J.Z., W.T., L.J., Q.W., R.W., Y.Z., G. Shi, G.F.G., Z.F.), the Hubei Provincial Center for Disease Control and Prevention, Wuhan, Hubei (X.G., Y.T., X.X., Y.W., Q.C., M.L., C.C., R.Y., S.Z., Y. Luo, B.Y.), the World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, University of Hong Kong, Hong Kong (P.W., K.S.M.L., E.H.Y.L., J.Y.W., T.T.Y.L., J.T.W., B.J.C., G.M.L.), the Chinese Field Epidemiology Training Program, Chinese Center for Disease Control and Prevention, Beijing (T.L., R.Y., S.Z., H. Liu, Y. Liu, G. Shao, H. Li, Z.T.), the Jingzhou Center for Disease Control and Prevention, Jingzhou, Hubei (T.L.), the Chengdu Center for Disease Control and Prevention, Chengdu, Sichuan (H. Liu); the Hunan Provincial Center for Disease Control and Prevention, Changsha, Hunan (Y. Liu), the Anyang Municipal Center for Disease Control and Prevention, Anyang, Henan (G. Shao), the Panjin Center for Disease Control and Prevention, Panjin, Liaoning (H. Li), the Guizhou Center for Disease Control and Prevention, Guiyang, Guizhou (Z.T.), the Jiading District Center for Disease Control and Prevention, Shanghai (Y.Y.), the Nanchang Center for Disease Control and Prevention, Nanchang, Jiangxi (Z.D.), the Inner Mongolia Comprehensive Center for Disease Control and Prevention, Hohhot, Inner Mongolia (B.L.), and the Baoshan District Center for Disease Control and Prevention, Shanghai (Z.M.) - all in China.

Abstract:  Background: The initial cases of novel coronavirus (2019-nCoV)-infected pneumonia (NCIP) occurred in Wuhan, Hubei Province, China, in December 2019 and January 2020. We analyzed data on the first 425 confirmed cases in Wuhan to determine the epidemiologic characteristics of NCIP. Methods: We collected information on demographic characteristics, exposure history, and illness timelines of laboratory-confirmed cases of NCIP that had been reported by January 22, 2020. We described characteristics of the cases and estimated the key epidemiologic time-delay distributions. In the early period of exponential growth, we estimated the epidemic doubling time and the basic reproductive number. Results: Among the first 425 patients with confirmed NCIP, the median age was 59 years and 56% were male. The majority of cases (55%) with onset before January 1, 2020, were linked to the Huanan Seafood Wholesale Market, as compared with 8.6% of the subsequent cases. The mean incubation period was 5.2 days (95% confidence interval [CI], 4.1 to 7.0), with the 95th percentile of the distribution at 12.5 days. In its early stages, the epidemic doubled in size every 7.4 days. With a mean serial interval of 7.5 days (95% CI, 5.3 to 19), the basic reproductive number was estimated to be 2.2 (95% CI, 1.4 to 3.9). Conclusions: On the basis of this information, there is evidence that human-to-human transmission has occurred among close contacts since the middle of December 2019. Considerable efforts to reduce transmission will be required to control outbreaks if similar dynamics apply elsewhere. Measures to prevent or reduce transmission should be implemented in populations at risk. (Funded by the Ministry of Science and Technology of China and others.). 

Retracted: No

PubPeer comments:
 What PCR-probes were used to identify 2019-nCoV. This [protocol is too non-specific] . Here is a [specific 500bp] unique to 2019-nCov - based on this pre-print. , 
 The [US CDC PCR-probes are also non-specific] - ie along with Wuhan coronavirus, it will also detect SARS, which may be much less dangerous. , 
 In this article, the authors clearly describes that there is evidence that human-to-human transmission has occurred among close contacts since the middle of December 2019. ![file] It s amazing that as China s largest disease monitoring and Prevention Center, the first thing is not to inform Chinese people how to prevent and treat this novel coronavirusu2013infected pneumonia, but to let this virus spread worldwide-this is intolerable to the people all over the world, especially the 1.3 billion Chinese. The concealment of researchers led to the Wuhan municipal health committee still releasing information on December 31, 2019 that this novel coronavirus could not be transmitted from human-to-human (http: wjw.wuhan.gov.cn front web showDetail 2019123108989) ![file] The author s concealment resulted in this novel coronavirus not being controlled in time and led to the widespread spread across China, which seriously harmed the life and health of Chinese people and seriously affected the development of China s economy. ![file] ![file] From virus onset to January 30, 2020 I deeply doubt whether this article meets the ethical requirements. Does Chinese people tolerate such behavior? , 
 #3 u201cDoes Chinese people tolerate such behavior?u201d Is this intended as a rhetorical question or are you asking for an analysis of how responsive is Chinau2019s government to pressure from the people living in China? It isnu2019t clear that either way you intend the question it would be something that the authors could address here. , 
 #3 You may be right or not about the delays and I won t discuss this here and certainly, the speed of the first response to such an outbreak, like for wildfires, determines the efficiency of its further control. However to be honest, I understand that the authors of this particular paper performed an ex-post analysis of the situation rather than working real-time, therefore not enabling them to issue an alert on time even if they had liked to. In addition, but this is a minor point, I cannot really find where the calculation leading to the date proposed is made in the paper. , 
 #3 Well, this paper is a retropespective study. They analyzed the data on Feb,2020, and concluded that human-to-human transmittion occurred on Dec,2019. Many clinical studies tracked the evidences years before the publication, but could still get significant conclusion. These scientist from China are not necessarily responsible for anything. Indeed, they did a nice work to get these research results, which was very useful for us to better understand the outbreak of this disease. ,