湖北省新型冠状病毒肺炎的流行特征及趋势分析

目的 本研究通过描述和分析新型冠状病毒肺炎（新冠肺炎）疫情期间湖北省罹患率、粗病死率等流行特征及趋势，为疫情的综合研判和防治措施效果评价提供参考。方法 通过对新冠肺炎疫情期间湖北省报告的病例数据，结合重大干预措施及事件时点，采用累计罹患率、新增病例环比增长率、新增病例定基增长率、观察-确诊转换率、累计粗病死率、每日重症率、死亡重症比等指标对疫情不同阶段的流行特征进行描述和分析。结果 湖北省的新冠肺炎疫情经历了1月10日至2月3日大量病例开始出现的暴发期，2月4－19日新增病例和死亡病例持续增加的高峰期，2月20日至3月3日新增确诊和新增治愈相持的平台期，3月4－18日病例减少和治愈增多的消退期。湖北省疫情累计罹患率从1月19日的0.03/万增加至3月18日的11.46/万，武汉市从1月10日的0.04/万发展至3月18日的45.13/万，湖北省其他地区从1月20日0.002/万发展至3月18日的3.70/万；新增病例增速在疫情期间有不同波动，湖北省全境增速在2月12日达到最高值；湖北省累计粗病死率从1月19日的1.01%增加到1月26日的5.13%后下降至2月13日的2.54%，之后缓慢增加到3月18日的4.62%，武汉市累计粗病死率趋势和湖北省一致，但略高；湖北省每日重症率从1月27日26.88%升高至3月18日34.27%，死亡重症比从1月23日7.37%下降至3月18日0.35%。结论 湖北省新冠肺炎流行的疫情周期为60 d，约为一个最长潜伏期或隔离期（14 d）和湖北省确诊患者平均住院时间（20 d）之和的1.76倍，提示我国陆续出台的重大抗疫决策效果显著。

Epidemic characteristics and trend analysis of COVID-19 in Hubei province

Objective By describing and analyzing the epidemic characteristics and trends of the attack rate, the crude mortality and relevant indexes in Hubei province during the pandemic of COVID-19 to provide comprehensive evaluations of the epidemic trends and the effects of intervention measures. Methods Based on the case data reported in Hubei province during the COVID-19 epidemic, combined with the important time of major interventions and event, the cumulative attack rate, the sequential increase rate of new cases, baseline increase rate of new cases, the observation- confirmed case conversion rate, the cumulative crude mortality, the daily severe case rate, and the ratio of death to severe were used to describe and analyze the epidemic characteristics in different phases of the COVID-19 epidemic. Results The epidemic experienced an outbreak phase from January 10 to February 3 with large amount of case reported, a peak phase from February 4 to February 19 with continuous increasing number of new cases and deaths, a platform phase from February 20 to March 3 with balanced diagnosis and treatment number, and a descending phase from March 4 to March 18 with decreased diagnosis and increased treatment number. Up to March 18, the cumulative attack rate of the COVID-19 epidemic in Hubei province increased from 0.03/10 000 on January 19 to 11.46/10 000, from 0.04/10 000 on January 10 to 45.13/10 000 in Wuhan city, and from 0.002/ 10 000 on January 20 to 3.70/ 10 000 in other areas of Hubei province other than Wuhan city. The increase rate of new cases fluctuated during the epidemic period and reached the highest at February 12 in Hubei province. The cumulative crude mortality in Hubei Province increased rapidly from 1.01% on January 19 to 5.13% on January 26, then decreased to 2.54% on February 13, and then slowly increased to 4.62% on March 18, and similar trend was also observed in Wuhan city. The daily severe rate in Hubei Province increased from 26.88% on January 27 to 34.27% on March 18. The ratio of death to severe decreased from 7.37% on January 23 to 0.35% on March 18. Conclusions The epidemic cycle of COVID-19 in Hubei province proposed to be 60 days, which was about 1.76 times of the combination of the longest incubation period or isolation period (14 d) and the average hospitalization time of confirmed patients in Hubei province (20 d). It suggested that the major anti-epidemic decisions made in China were effective.