西宁市2起新型冠状病毒肺炎聚集性疫情流行病学特征分析  

Epidemiological characteristics analysis of two clusters of COVID-19 in Xining City

作　　者：曹海兰[1] 马永成[1] 赵建海[1] 马斌忠[1] 马小军[1] 张华一[1] 赵金华[1] 丁小津 胡玉芬 陈露 CAO Hailan;MA Yongcheng;ZHAO Jianhai;MA Binzhong;MA Xiaojun;ZHANG Huayi;ZHAO Jinhua;DING Xiaojin;HU Yufen;CHEN Lu(Qinghai Center for Disease Prevention and Control,Xining 810007,Qinghai Province,China)

机构地区：[1]青海省疾病预防控制中心,西宁810007

出　　处：《寄生虫病与感染性疾病》2023年第3期136-139,145,共5页Parasitoses and Infectious Diseases

基　　金：国家科技重大专项(项目编号:2017ZX10303404005003);传染病预防控制国家重点实验室自主研究重点课题(项目编号:2018SKLID101)。

摘　　要：目的分析西宁市2起新型冠状病毒肺炎(COVID-19,新冠肺炎)聚集性疫情的流行病学特征,探讨相关防控对策。方法采用描述流行病学方法对2021年西宁市2起新冠肺炎聚集性疫情的流行病学特征进行回顾性描述,计算潜伏期和代际间隔。结果2021年西宁市2起聚集性疫情病例共11例,其中8例为本地续发病例;病例平均年龄(40.91±16.34)岁;首发症状主要是咽痛(54.55%)和咳嗽(54.55%);病例分型以普通型和轻型为主(81.82%);病例平均潜伏期为3 d,代际间隔中位数为3 d(IQR:2,4);11例病例首次核酸检测阳性样本中,有8例Ct值≤34。1~4号病例病毒基因测序均属于VOC/Delta变异株(B.1.617.2进化分支),与外省G市确诊病例基因组高度同源。结论2021年西宁市2起新冠肺炎聚集性疫情的传播链为首发病例于外省旅行途中接触已感染人群,造成家庭内传播,而后相关人员在病例家中开展活动时不慎感染,再经同一公共场所内密切接触传播。应重视有中高风险地区旅居史返乡人员的疫情防控工作,在疫情发生初期采取快速管控措施,可以有效阻止疫情的扩散。Objective To analyze the epidemiological characteristics of two clusters of COVID-19 in Xining City,and to discuss the prevention and control measures.Methods The descriptive epidemiological analysis method was used to describe the epidemiological characteristics of the two outbreaks,and the incubation period and intergenerational interval were calculated.Results A total of 11 cases involved in 2 clusters of epidemics,of which 8 were local secondary cases.The average age of the cases was(40.91±16.34)years old.The first symptoms were mainly sore throat(54.55%)and cough(54.55%).The main types of cases were normal and mild(81.82%).The average incubation period was 3 days,and the median interval between generations was 3 days(IQR:2,4).Among the 11 cases with positive nucleic acid test samples for the first time,Ct values of 8 cases were≤34.The virus gene sequencing of cases 1-4 belonged to VOC/Delta variant strains(B.1.617.2 evolutionary branch),and it was highly homologous to the genomes of confirmed cases in G city in other provinces.Conclusions The chain of transmission of clustered outbreaks in Xining was that the first case came was in contact with infected people during travels from other provinces,which caused transmission within the family,and then the relevant personnel were accidentally infected while working in the case's home,then spread through close contact in the same public place.It is necessary to pay attention to the epidemic prevention and control work of returnees.Taking rapid control measures in the early stage of the epidemic can effectively prevent the spread of the epidemic.

关 键 词：COVID-19 聚集性疫情 流行病学特征 传播链 防控对策 

分 类 号：R181.3[医药卫生—流行病学] R563.1[医药卫生—公共卫生与预防医学]