基于早期外地病例数据估计新型冠状病毒肺炎疫情中心武汉市患者人数每日趋势

Estimating The Daily Trend in the Number of COVID-19 Patients in the Epicenter Wuhan Based on Imported Cases in the Early Stage

自2019年12月以来,中国湖北省武汉市爆发了严重的新型冠状病毒肺炎疫情.在此次疫情的早期阶段,由疫情中心武汉市输入到全国乃至全世界的病例成为各地新型冠状病毒肺炎传播的主要来源.根据各地从武汉市输入病例的信息可以反推出武汉市新型冠状病毒肺炎的实际感染情况.本文旨在通过由公开数据获得的湖北省以外在疫情爆发早期确诊的10940例病例信息,估计出自疫情爆发以来武汉市每日的累计感染人数,并预测武汉市新型冠状病毒肺炎疫情的走向.本文基于2020年1月23日以前离开武汉并在湖北省以外被确诊的病例信息,对武汉市从2020年1月10日至2020年3月19日之间每日应报告累计确诊人数以及报告率进行估计,并估计出首例感染病例出现日期.鉴于许多病例的公开信息中并不包含其是否去过武汉,直接进行统计推断可能造成估计偏差.本文对缺失数据采用双重稳健方法进行处理,以得到更为准确的估计结果.研究结果表明,武汉市在2020年2月引入临床诊断是对当时诊断方案的一个行之有效的补充.截至2020年3月19日,武汉市新型冠状病毒肺炎疫情已经基本得到控制.

There has been an outbreak of coronavirus disease(COVID-19) in Wuhan city,Hubei province,China since December 2019.In the early stage of the outbreak,cases imported from the epicenter Wuhan to other parts of China and the whole world became the main source of COVID-19 transmission.The information of imported cases can be used to infer the actual number of patients in Wuhan.We provide estimates of the daily trend in the size of the epidemic in Wuhan based on the detailed information of 10,940 confirmed cases outside Hubei province retrieved from publicly availiable records and predict the development of this epidemic in Wuhan.In this modelling study,we estimate the epidemic size and reporting rate in Wuhan from January 10,2020,to March 19,2020,based on the confirmed cases outside Hubei province that left Wuhan by January 23,2020.We also estimate the date when the first patient was infected.Since some confirmed cases have no information on whether they visited Wuhan before,ordinary statistical inference could be biased.We implement the double robust method to the missing data to obtain more accurate results.The results indicate that the introduction of clinical diagnosis in Wuhan in February 2020 is an effective complement to the confirmation method at that time.As of March 19,2020,the transmission of COVID-19 in Wuhan has been controlled.