Sequence analysis of varicella-zoster virus in Nantong,Jiangsu province in 2023
Objective To reveal the molecular epidemiological characteristics of varicella-zoster virus(VZV)in the 2023 varicella outbreak in Nantong,Jiangsu,by performing genetic typing and whole-genome sequencing of VZV-positive samples,and provide scientific evidence for varicella outbreak prevention and control.Methods A total of 61 throat swabs and herpes fluid samples from 11 public health emergencies were collected and tested for VZV using quantitative real-time polymerase chain reaction(qPCR).Samples with qPCR positive and Ct values ≤30 were selected for amplification and sequencing of ORF22,ORF38,and ORF62 gene fragments for genotyping and identification of wild strains and vaccine strains.Whole genome sequencing was performed on samples with Ct values ≤25,and a phylogenetic tree was constructed.The samples were compared with the 9 nucleocapsid glycoproteins of the domestic vaccine strain Baike for analysis.Results The VZV positive rate in the samples was 73.78％(45/61).The genotyping results showed that the nucleotides of the single nucleotide polymorphism sites(37902,38019,38055,38081,38177,and 69424)were G,G,C,C,A,and G,respectively,which were consistent with the Clade 2 reference strain.All samples were wild strains.Whole genome sequencing and phylogenetic tree analysis further confirmed this result.Comparison of nucleocapsid glycoprotein sequences showed that the local strain and the vaccine strain Baike were highly conserved,with the identities of gK,gN,and gL being 100％,the nucleotide identities of gH,gM,and gE being 99.88％,99.85％,and 99.95％,respectively,and the nucleotide identities of gC,gB,and gI ranging from 99.41％to 99.92％.Conclusions The VZV in the 2023 varicella epidemic in Nantong mainly belonged to Clade 2 and was mainly a wild strain.The current varicella vaccine had good safety and efficacy,but attention should be paid to the slight variation of nucleocapsid glycoproteins gC,gB,and gI.The results provide new data for the molecular epidemiological characteristics of VZV and provide a scientific basis for the formulation of varicella prevention and control measures.
NETL
NSTL
万方数据
