【Abstract】
Since December 2019, an outbreak of novel coronavirus (SARS-CoV-2) that began from Wuhan, Hubei Province, has rapidly spread to 34 provincial-level divisions of China. Faced with such a grim situation, the Chinese government has taken a series of unprecedented rigorous measures, including initiation the highest level of responding mechanism for major public health emergency, shutting down all outbound transportation channels of Wuhan city, extension of the Spring Festival holiday and winter vacation, building and renovation of temporary hospitals, recruitment of health workers heading out to Wuhan and other cities in Hubei Province. Using a real-time Bayesian estimation model and a reported serial interval of COVID-19, we computed time-dependent reproduction number, R(t). R(t) has showed a downward trend in Wuhan, Hubei Province, outside Hubei, and China from January 27, 2020, to February 10, 2020. The downward trend of R(t) indicates that the prevention and control measures may be effective. However, we still confront a number of great challenges, including: the source of SARS-Cov-2 remains pendent, other transmission routes need to be identified, the existence of asymptomatic cases, and the large-scale of population migration due to work resumption.
【中文摘要】
自2019年12月以来，新型冠状病毒（SARS-CoV-2）从湖北武汉爆发，并迅速蔓延至中国34个省级地区。面对如此严峻的形势，中国政府启动了最高级别的重大突发公共卫生事件应急机制，封闭武汉交通枢纽，延迟复工复学，新建及改造临时医院，各地医护人员驰援武汉等一系列措施控制感染进一步扩散。利用实时贝叶斯估计模型和COVID-19的感染序列区间，我们计算了COVID-19的时间依赖性的再生指数R（t）。结果显示，从2020年1月27日到2020年2月10日，武汉市、湖北省、湖北省以外地区和中国的总体R（t）均呈下降趋势。R（t）的下降趋势表明，中国政府的防治措施可能是有效的。但中国对于COVID-19的防控仍面临巨大挑战，包括：SARS-Cov-2来源尚未明确，传播途径需进一步明确，无症状感染者的存在，复工复产带来的大规模人口迁移。