一起奥密克戎变异株引起的新型冠状病毒感染本土疫情流行特征与传播动力学分析  

Epidemiological characteristics and transmission dynamics of alocal outbreak of COVID-19 caused by Omicron variant

作　　者：杨云斌[1] 戚艳波[1] 刘春桃 邢漪[1] 王晓雯[1] 李玲[1] 刘良丽 左仕富 YANG Yunbin;QI Yanbo;LIU Chuntao;XING Yi;WANG Xiaowen;LI Ling;LIU Liangli;ZUO Shifu(Yunnan Center for Disease Control and Prevention,Kunming,Yunnan 650022,China)

机构地区：[1]云南省疾病预防控制中心,云南昆明650022

出　　处：《中国预防医学杂志》2023年第7期743-746,共4页Chinese Preventive Medicine

摘　　要：目的 分析云南省边境某县一起由奥密克戎变异株(BA. 2)引起的新型冠状病毒感染(新冠)本土疫情的流行特征及传播动力情况,为今后新冠疫情防控策略制定提供参考依据。方法 收集2022年4月8—25日云南省边境某县报告新冠阳性病例的个案信息和流行病学调查资料,采用描述流行病学方法及传染病传播动力学方法进行分析。结果 本次疫情共报告202例病例,经测序为奥密克戎变异株BA. 2;男女性别比1∶1.6,各年龄段、不同疫苗接种史的人群均有发病;出现51个家庭聚集性发病;潜伏期(2.38±2.20) d,代间距(2.85±2.11) d;实时再生数(Rt)最高时达到4.76 (95%CI:3.37~6.39),但在实施防控措施约9 d后,Rt迅速下降至1以内,与防控效果相呼应。结论 奥密克戎变异株的潜伏期短、代际传播时间短、传播隐匿且速度快、容易造成聚集性发病,防控部门应进行早期疫情研判和采取有效的防控措施,对及时、快速地控制住疫情态势发展具有至关重要的作用。Objective To analyze the epidemiological characteristics and transmission dynamics of a local outbreak of COVID-19 caused by Omicron(BA.2)variant in a border county in Yunnan,so as to provide reference for the formulation of COVID-19 prevention and control strategies in the future.Methods The case information and epidemiological investigation data of COVID-19 positive cases reported in a border county in Yunnan from April 8 to 25,2022 were collected and analyzed using descriptive epidemiological methods and infectious disease transmission dynamics methods.Results A total of 202 cases were reported in this outbreak,which,according to sequence results,was caused by Omicron variant(BA.2).The male-to-female ratio was 1∶1.6.The disease occurred in people of all ages and with different vaccination histories.There were 51 family aggregations.The average incubation period was(2.38±2.20)d and the generation interval was(2.85±2.11)d.The highest reproduction number(Rt)reached 4.76(95%CI:3.37-6.39),but it rapidly decreased to less than 1 after about 9-days’prevention and control measures,which echoed the prevention and control effect.Conclusions Omicron variant has short incubation period,short generation time,occult and fast transmission,and may easily cause aggregated disease outbreak.Disease prevention and control department should carry out early epidemic investigation,form quick decisions,and take effective prevention and control measures,which plays a vital role in timely and promptly controlling the development of epidemics.

关 键 词：新型冠状病毒感染 奥密克戎 流行特征 再生数 

分 类 号：R181.3[医药卫生—流行病学]