Analysis of genomic characteristics of SARS-CoV-2 imported from abroad through Changchun Customs
To understand the demographic characteristics of imported patients with Coronavirus Disease 2019(COVID-19)and the whole genome variation of SARS-CoV-2 through Changchun Customs.The case information of 27 patients with COVID-19 imported through Changchun Customsfrom April to December 2023 was collected.The RT-PCR method was used to detect the nucleic acid of respiratory tract samples.The Ct values of ORF1ab gene and N gene were between 25 and 30,accounting for 55.56%.The whole genome of the virus was analyzed by the third-generation nanopore gene sequencer sequencing and the whole genome analysis V1.0 software,and the sequencing coverage was 98.02%-99.59%.Compared with the Wuhan reference strain(NC_045512.2),the number of nucleotide mutation sites in the SARS-CoV-2 genome sequence was between 62 and 132.Pangolin typing showed that all of them were Omicron mutant strains,EG.5.1 and its sub-branches accounted for the largest proportion,accounting for 25.93%.By analyzing the nucleic acid and gene sequence of the novel coronavirus of entry personnel at the ports through Changchun Customs and monitoring the import of SARS-CoV-2 abroad,the variation trend of the virus strain can be grasped in real time.