Genetic diversity and molecular evolution of Seoul virus in Hebei province, China.

Seoul virus (SEOV) is a major pathogen which causes hemorrhagic fever with renal syndrome (HFRS), and is present all over the world. However, there are currently few long-term systematic studies of SEOV's phylogenetic and evolutionary mechanisms in epidemic areas. Thus, in this study, we used RT-PCR combined with NGS to obtain the genomes of six SEOV viruses from 1993, as well as 56 Hebei province-specific tissue samples from 1999 to 2022. Phylogenetic analysis showed that the SEOV samples could be divided into seven groups and showed geographic clustering. The geographic region may be the main factor affecting the genetic diversity of SEOV. We also found that SEOV was subject to strong overall purifying selection and positive selection at certain sites during evolution. Recombination events and high nucleotide substitution rates were also shown to accelerate SEOV's evolution. Evolutionary feature of the L segment is more representative of complete genome. Our detailed analysis provides a deeper understanding of the genetic diversity and evolutionary drivers of SEOV within its primary epidemic areas. It will be important to further monitor epidemiological trends and drivers of variation to help increase our understanding of the pathogenicity of SEOV infections.