Objective To analyze the genomic characteristics of the monkeypox virus (MPXV) strains isolated from local cases in Ji′nan city, Shandong province.

Methods Blood serum and vesicular fluid samples from suspected cases of MPXV infection reported in Ji′nan city from June to October 2023 were tested for MPXV nucleic acids. The complete genome sequence of MPXV was obtained using whole-genome sequencing (WGS) technology. Molecular genetic evolution of the MPXV genome sequence was performed using Mega 11 software, Bioedit software, and the Nextclade online comparison website. Systematic phylogenetic trees and nucleotide and amino acid sequence mutation analyses were performed.

Results In this study, the complete genome sequences of 7 strains of MPXV isolated from the cases in Ji′nan city were obtained by WGS, with a total genome length of 196 858 bp. The online comparison results uploaded to the Nexttrade website showed that all of them belonged to the IIb branch of the West African branch, and the lineage classification was C.1. The number of nucleotide variations with a depth greater than 50% is 86, and the total number of variations with an effect of ≥ intermediate is 39.

Conclusion The evolutionary distance between the sequences of MPXV strains isolated in Ji′nan city and those in China is relatively close, belonging to the same evolutionary branch, and no new branches have been found.