基于时变再生数的上海市新型冠状病毒奥密克戎疫情趋势评估  

Assessment of COVID-19 Omicron epidemic trend in Shanghai based on time-varying reproduction number

作　　者：刘芷希 朱文龙[1] 王伟炳[1] LIU Zhixi;ZHU Wenlong;WANG Weibing(School of Public Health,Fudan University,Shanghai 200032,China)

机构地区：[1]复旦大学公共卫生学院,上海200032

出　　处：《上海预防医学》2022年第6期541-544,共4页Shanghai Journal of Preventive Medicine

摘　　要：【目的】通过估计时变再生数(Rt),评估上海市新型冠状病毒奥密克戎(Omicron)疫情的变化趋势和防控措施效果。【方法】根据2022年2月20日—2022年4月26日上海市每日报告确诊病例、无症状感染者数据,采用贝叶斯框架方法搭建的R软件包“Epiestim”估计流行期间Rt的变化曲线,分析判断疫情趋势。【结果】疫情前期,实施学校停课、部分社区核酸筛查的措施后,Rt持续波动于2.000~3.000,于2022年3月21日达峰值2.740(95%CI:2.640~2.830)。2022年4月1日上海市实施全域封控措施后1周左右,Rt值开始呈下降趋势。截至2022年4月19日,上海市Rt首次低于阈值1.000,达0.955(95%CI:0.951~0.961)。【结论】上海市实施防控强度逐级上升的公共卫生措施后,传播速度逐步下降,体现出上海市干预措施已有一定效果。在实际防疫过程中,防控工作仍不能有丝毫放松,才能将Rt保持于1.000以下。[Objective]To assess the epidemic trend of COVID-19 Omicron and the effectiveness of containment measures in Shanghai by estimating the time-varying reproduction number(Rt).[Methods]Based on the daily reported confirmed cases and asymptomatic infections in Shanghai from February 20 to April 26,2022,the R package "Epiestim",which was built by Bayesian framework method,was used to estimate the variation curve of Rt during the epidemic period and to analyze the trend of the epidemic.[Results]In the early stage of the epidemic,after the implementation of school closure and nuclear acid screening in some communities,Rt continued to fluctuate between 2.000and 3.000,reaching a peak of 2.740(95%CI:2.640-2.830)on March 21,but began to decline around one week after the city lock-down on April 1. As of April 18,the Rt value in Shanghai was below the threshold of 1.000 for the first time,reaching 0.955(95%CI:0.951-0.961).[Conclusion]After the implementation of public health measures with increasing strength of containment in Shanghai,the transmission rate gradually decreased,reflecting the effectiveness of the interventions. In the actual prevention and control process,the containment work should not be relaxed in order to keep the Rt below 1.000.

关 键 词：新冠病毒肺炎疫情 Omicron变异株 公共卫生措施 时变再生数 

分 类 号：R183[医药卫生—流行病学]