中國武漢2019-nCoV爆發的國內外疫情預測

中國武漢2019-nCoV爆發的國內外疫情預測

作者：

小柯機器人

發布時間：2020/2/11 10:06:41

香港大學李嘉誠醫學院、世界衛生組織傳染病流行病學和控制合作中心Joseph T Wu研究組宣布他們對2019-nCoV爆發的國內外疫情進行了預測。相關論文發表在2020年1月31日出版的《柳葉刀》雜誌上。

自2019年12月31日以來，中國武漢市報告了由2019新型冠狀病毒（2019-nCoV）引起的非典型肺炎疫情。病例已擴散至中國其他城市以及其他國家，有可能引發全球疫情。研究組根據武漢向中國大陸以外城市擴散的病例數量，對武漢的疫情規模進行了估計，並預測了國內和全球流行病的公共衛生風險程度，同時考慮了社會和非藥物預防幹預措施。

研究組利用2019年12月31日至2020年1月28日武漢市國際擴散病例數（已知症狀發生日為2019年12月25日至2020年1月19日）的數據，推斷武漢市2019年12月1日至2020年1月25日的感染人數。然後對國內擴散病例進行估計。

研究組預測了2019-nCoV在全國和全球的傳播，並考慮了武漢及周邊城市從2020年1月23日至24日開始實施的大城市範圍隔離的影響。採用易感-暴露-感染-恢復的集合種群模型模擬我國各大城市的疫情。

在研究組的基線預測中，截至2020年1月25日，預計武漢市2019-nCoV的基本繁殖數為2.68，流行倍增時間為6.4天。研究組還估計，在基線預測下，重慶、北京、上海、廣州和深圳分別從武漢輸入461例、113例、98例、111例和80例感染者。如果2019-nCoV在國內各地的傳播率相似，隨著時間的推移，研究組推斷，中國多個主要城市的流行病已經呈指數增長，將滯後於武漢爆發約1-2周。

因為考慮到2019-nCoV已不僅在武漢範圍內，所以中國其他主要城市也正在努力控制局部疫情。與中國交通聯繫密切的海外大城市也可能成為疫情爆發的中心，除非立即在人口和個人兩個層面實施大規模的公共衛生幹預措施。因為大量症狀前病例擴散和缺乏大規模公共衛生幹預措施，全球主要城市的獨立自持爆發可能無法避免。研究組建議應在全球迅速部署備災計劃和緩解措施。

Title: Nowcasting and forecasting the potential domestic and international spread of the 2019-nCoV outbreak originating in Wuhan, China: a modelling study

Author: Joseph T Wu, Kathy Leung, Gabriel M Leung

Issue&Volume: January 31, 2020

Abstract: BackgroundSince Dec 31, 2019, the Chinese city of Wuhan has reported an outbreak of atypical pneumonia caused by the 2019 novel coronavirus (2019-nCoV). Cases have been exported to other Chinese cities, as well as internationally, threatening to trigger a global outbreak. Here, we provide an estimate of the size of the epidemic in Wuhan on the basis of the number of cases exported from Wuhan to cities outside mainland China and forecast the extent of the domestic and global public health risks of epidemics, accounting for social and non-pharmaceutical prevention interventions.MethodsWe used data from Dec 31, 2019, to Jan 28, 2020, on the number of cases exported from Wuhan internationally (known days of symptom onset from Dec 25, 2019, to Jan 19, 2020) to infer the number of infections in Wuhan from Dec 1, 2019, to Jan 25, 2020. Cases exported domestically were then estimated. We forecasted the national and global spread of 2019-nCoV, accounting for the effect of the metropolitan-wide quarantine of Wuhan and surrounding cities, which began Jan 23–24, 2020. We used data on monthly flight bookings from the Official Aviation Guide and data on human mobility across more than 300 prefecture-level cities in mainland China from the Tencent database. Data on confirmed cases were obtained from the reports published by the Chinese Center for Disease Control and Prevention. Serial interval estimates were based on previous studies of severe acute respiratory syndrome coronavirus (SARS-CoV). A susceptible-exposed-infectious-recovered metapopulation model was used to simulate the epidemics across all major cities in China. The basic reproductive number was estimated using Markov Chain Monte Carlo methods and presented using the resulting posterior mean and 95% credibile interval (CrI).FindingsIn our baseline scenario, we estimated that the basic reproductive number for 2019-nCoV was 2·68 (95% CrI 2·47–2·86) and that 75815 individuals (95% CrI 37304–130330) have been infected in Wuhan as of Jan 25, 2020. The epidemic doubling time was 6·4 days (95% CrI 5·8–7·1). We estimated that in the baseline scenario, Chongqing, Beijing, Shanghai, Guangzhou, and Shenzhen had imported 461 (95% CrI 227–805), 113 (57–193), 98 (49–168), 111 (56–191), and 80 (40–139) infections from Wuhan, respectively. If the transmissibility of 2019-nCoV were similar everywhere domestically and over time, we inferred that epidemics are already growing exponentially in multiple major cities of China with a lag time behind the Wuhan outbreak of about 1–2 weeks.InterpretationGiven that 2019-nCoV is no longer contained within Wuhan, other major Chinese cities are probably sustaining localised outbreaks. Large cities overseas with close transport links to China could also become outbreak epicentres, unless substantial public health interventions at both the population and personal levels are implemented immediately. Independent self-sustaining outbreaks in major cities globally could become inevitable because of substantial exportation of presymptomatic cases and in the absence of large-scale public health interventions. Preparedness plans and mitigation interventions should be readied for quick deployment globally.

DOI: 10.1016/S0140-6736(20)30260-9

Source: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30260-9/fulltext