广州市一起由新型冠状病毒Delta变异株引起的家庭聚集性疫情流行病学调查

Epidemiological investigation of a family clustering of COVID-19 caused by SARS-CoV-2 Delta variant in Guangzhou,China

目的分析广州市一起由Delta变异株(B.1.617.2)引起的COVID-19家庭聚集性疫情的流行病学特征,为相关疫情防控提供参考。方法从中国疾病预防控制中心传染病报告管理信息系统和流行病学调查资料获取病例信息,采用描述性流行病学方法对该起疫情的调查和特征进行分析描述。结果该起家庭聚集性疫情涉及6名确诊病例,其中男、女各3人,中位年龄为24.50岁,均无新型冠状病毒(简称新冠)疫苗接种史。病例1~4与确诊病例在某餐厅有同时段用餐史,在暴露后4~7 d陆续发病;家庭成员病例5、6则分别在病例1~4发病后2~5 d发病。除病例1、2是由社区集中核酸检测发现,其余4人均是作为病例1、2的密切接触者在集中隔离观察中检测发现。6名病例活动轨迹累计涉及24个重点场所,共甄别密切接触者427人,除病例3~6外无续发感染。结论结合疫苗接种和非药物类控制措施,重点关注和控制家庭聚集性发病,仍是阻断COVID-19疫情社区传播的重要策略。

Objective To investigate the epidemiological characteristics of a family clustering of COVID-19 caused by SARS-CoV-2 Delta(B.1.617.2)variant in Guangzhou,China.Methods The information of this case were extracted from Chinese CDC Infectious Disease Information System and epidemiological investigation.Demographic and epidemiological characteristics of this case were analyzed and described through descriptive epidemiological analysis.Results This family clustering included 6 cases,3 of them were male,and the median age was 24.50 years.None of them accepted vaccination.4 cases(case 1-4)of them developed symptoms successively 4-7 d after they had an exposure history in a restaurant with a confirmed case.Due to close contact,the other two family members(case 5,6)developed symptoms 2-5 d after the onset of the 4 cases aforementioned.Case 1 and 2 were found after taking the centralized nucleic acid testing of SARS-CoV-2 in the community,case 3-6 were reported during the centralized health observation as the close contacts of case 1 and 2.A total of 24 key locations were involved in the activity trajectories of the 6 cases,and 427 close contacts were found.Except for other 4 cases,none of the close contacts were infected.Conclusions With vaccination and non-pharmaceutical interventions,focusing on stopping transmitting in family is still an important and useful strategy in preventing and controlling the community transmission of COVID-19 epidemic.