广西境外输入性COVID-19感染者流行病学及病毒基因特征

Epidemiological and genetic characteristics of imported COVID-19 cases in Guangxi

目的分析广西壮族自治区(广西)境外输入性COVID-19感染者的流行病学特点及病毒基因特征,为境外输入疫情防控提供依据。方法收集2020年3月1日―2022年3月31日广西境外输入性COVID-19感染者的相关信息,使用CLC Genomics Workbench软件进行序列拼接,MEGA软件构建系统进化树。结果广西累计报告输入性感染者1662例,纳入分析1643例,平均年龄为37.4岁,男女比例为6.4∶1,68.4%接种过疫苗。输入性感染者来源国以越南为主(92.5%),入境口岸以凭祥友谊关为主(87.4%)。2020年输入性感染者主要为B.1.351和B.1.1分支,2021年主要为Delta分支,2022年主要为Omicron分支。结论广西持续存在从东南亚疫情高风险国家通过口岸输入疫情的风险,输入感染者的病毒主要为当年的关切变异株(variants of concern,VOC),口岸疫情防控形势严峻,需要持续关注输入性病例。

Objective To analyze epidemiological and genetic characteristics of imported COVID-19 cases in Guangxi,and to provide scientific evidence for risk assessment and control strategies for imported COVID-19 in Guangxi.Methods The data of imported cases reported in Guangxi from March 1,2020 to March 31,2022 were collected.Whole genome sequencing was performed on samples that met sequencing criteria.CLC Genomics Workbench software was used for sequence assembly and analysis.A phylogenetic tree was constructed using MEGA software based on the neighbor-joining method.Results A total of 1662 imported cases of COVID-19 were reported in Guangxi,of which 1643 cases were included in the analysis.The average age was 37.4 years old.The male to female ratio of the cases was 6.4∶1.And the cases that had been vaccinated accounted for 68.4%.The imported cases could obviously be attributed to the increased importation of COVID-19 mainly from Vietnam,accounting for 92.5%,and 87.4%of cases came from Pingxiang Friendship Gate.The genotyping of imported cases mainly were the branch of B.1.351 and B.1.1,Delta,Omicron in 2020,2021,and 2022,respectively.Conclusions Guangxi is at high risk of experiencing an epidemic of imported COVID-19 cases from Southeast Asia.The imported cases of SARS-CoV-2 were mainly variants of concern(VOC)from the same year.The focus on preventing imported cases should be on sustainable strategies for port cities.