2019新型冠状病毒肺炎疫情传播能力及疫情控制效能的地域差异分析

Analysis of Transmissibility of COVID-19 and Regional Differences in Disease Control

2019年底武汉突发的新型冠状病毒疾病(COVID-19)疫情已进入"全球大流行"状态.本文基于Li等(New England Journal of Medicine,2020,382:1199-1207)关于2019年12月10日至2020年1月4日期间武汉最早的425例确诊病例数据,使用似然函数估计方法得到了COVID-19疫情的基本再生数为2.42,平均序列间隔为8.85天.为了刻画疾病瞬时传播能力的地域差异,利用湖北省内各地市和中国境内各省市的每日疫情报告数据(来自各省市卫生健康委员会网站),由统计模型得到了各地在2020年2月间的每日瞬时再生数估计值.进一步,基于瞬时再生数定义了一个新的疫情控制效能公式,定性评估了各地区采取的防控策略对COVID-19实时传播能力的影响.结果提示现阶段境外输入病例造成国内疫情复发的风险依然很大,COVID-19传播具有较明显的地域差异,但引起差异的因素值得后续进一步持续关注.

The outbreak of novel coronavirus disease(COVID-19) in Wuhan in late 2019 has entered the "global pandemic" state.Based on the data on the first 425 confirmed cases in Wuhan from December 10,2019 to January 4,2020,this paper uses Maximum Likelihood Estimate method to obtain the basic reproduction number of COVID-19 outbreaks,which is2.42,and the mean serial interval,which is 8.85 days.In order to characterize the regional differences in the transient transmission capacity of the disease,the daily report data of cities in Hubei Province and the other provinces and cities in China were used to obtain an estimated daily basic reproduction number of each region in February 2020 on the basis of the statistical model.Further,this paper defines a new epidemic control effectiveness formula based on the instantaneous reproduction number,and qualitatively evaluates the influence of the control strategies adopted in each region on the real-time transmission capacity of COVID-19.The results indicate that the risk of recurrence of the domestic epidemic is still high due to the imported cases at this stage,and there are obvious regional differences in the spread of COVID-19,but the factors that cause the differences deserve further follow-up.