陕西省新型冠状病毒肺炎疫情的早期传播动力学研究

Early transmission dynamics of COVID-19 in Shaanxi Province

目的探讨陕西省新型冠状病毒肺炎(COVID-19)疫情早期的演变规律,为优化疫情防控策略、评估干预措施效果提供科学依据。方法收集陕西省2019年12月31日-2020年2月13日官方网络报道的疫情数据和中国疾病预防控制信息系统中的个案数据,同期人口数据来源于陕西省统计年鉴,采用Excel、ArcGIS软件开展COVID-19的描述性流行病学分析,采用BerkeleyMadonna软件实验平台构建COVID-19疫情的传播动力学模型,分析疾病发生发展规律。结果陕西省截止2020年2月13日累计报告COVID-19确诊病例230例,罹患率约为0.59/100000;男性发病数多于女性,40~50岁病例数最多;高发病地区主要分布在西安市、安康市、汉中市。SEIAR模型分析显示,陕西省疫情的基本再生指数R0约为2.95,模型结果2020年2月初是陕西省COVID-19发病的高峰期。结论陕西省COVID-19疫情呈快速扩散趋势,SEIAR模型预测的理论发病数可以为COVID-19疫情防控提供依据,遏制疫情蔓延。

OBJECTIVE To explore the early features of COVID-19 epidemic in Shaanxi Province so as to provide scientific basis for optimizing the prevention strategies and evaluating the effects of interventions. METHODS The epidemic data that were reported through official networks of Shaanxi Province from Dec. 31, 2019 to Feb. 13, 2020 and the case data from Chinese Information System for Disease Control and Prevention were collected, the population data during the same period were obtained from Shaanxi Statistical Yearbook. The descriptive epidemiological analysis was performed by using Excel and ArcGIS software, the transmission dynamics model of COVID-19 was built based on Berkeley Madonna software experiment platform, and the rules of occurrence and progression of the disease were observed. RESULTS By Feb. 13, 2020, the accumulative confirmed cases of COVID-19 reached 230 in Shaanxi Province, and the incidence rate was about 0.59 per 100 000. The male cases were more than the female cases, and the patients aged between 40 and 50 years old were dominant. The COVID-19 was highly prevalent in Xi’an, Ankang and Hanzhong. The SEIAR model showed that the basic regeneration index(R0) of the epidemic in Shaanxi Province was about 2.95, concluding that the beginning of Feb. 2020 was the peak period of outbreak of COVID-19 in Shaanxi Province. CONCLUSION The COVID-19 epidemic in Shaanxi province shows a fast spreading trend. The theoretical number of confirmed cases that is predicted based on the SEIAR model can provide basis for prevention and control of the COVID-19 epidemic and curb the spread of the epidemic.