2022年6-12月济南市境外输入性新冠肺炎流行病学和基因特征分析

Epidemiological and genetic characteristics analysis of abroad imported COVID-19 in Jinan from June to December,2022

目的分析境外输入新冠病毒的流行特征和基因组特征,为济南疫情防控工作提供参考依据。方法收集济南航空口岸2022年6-12月境外输入新冠病毒感染者相关信息,分析其流行病学特征,筛选77例感染者样本使用二代测序技术进行高通量测序,分析基因分型及变异特征。结果2022年6-12月,济南航空口岸累计报告输入性新冠病毒无症状感染者165例,男女性别比2.17∶1,平均年龄37.46岁;67.27%感染者接种过疫苗;职业以务工工人为主,占26.67%;来源国家主要是韩国,占21.21%。共获得77条有效的全基因组序列,按照Nextstrain分型法可分为8个型,均为Omicron变异株,优势进化分支主要是BA.2、BA.5.2及BA.5.10.1。系统发育分析表明,境外输入新冠病毒感染者的序列与来源国家的毒株序列高度同源。结论济南航空口岸境外输入新冠病毒风险持续存在,在及时跟踪疫情动态的同时,变异监测及防控措施仍需坚持不懈。

Objective To analyze the epidemical and genomic characteristics of abroad imported SARS-CoV-2,so as to provide scientific basis for the epidemic prevention and control at Jinan port.Methods The epidemiological characterization of information related to SARS-CoV-2 infections imported from abroad from June to December 2022 was collected from Jinan port.Seventy-seven infections’samples were screened for high-throughput sequencing using the second-generation sequencing technology analyzed for genotyping and variant features.Results A total of 165 cases of imported asymptomatic SARS-CoV-2 infection were reported at Jinan port,with a gender ratio of 2.17∶1,average age 37.46 years old,67.27%of those infected had been vaccinated.Occupations were mainly migrant workers,accounted for 26.67%.The main source country was South Korea,accounted for 21.21%.The 77 effective whole genome sequences could be divided into 8 types according to Nextstrain typing,all of which were Omicron variants,and the dominant evolutionary branches were BA.2,BA.5.2 and BA.5.10.1.Phylogenetic tree analysis showed that the sequences of imported SARS-CoV-2 infections were highly homologous to those of the source countries.Conclusion The risk of overseas importation of SARS-CoV-2 at Jinan port will continue to exist.Mutation surveillance and prevention and control measures still need to be persevered while tracking the epidemic situation in a timely manner.