2024年四川省登革热实验室检测阳性病例分子流行病学分析OA

This study explored the epidemiological characteristics and genetic features of dengue virus(DENV)strains in Sich-uan Province in 2024,to provide data to support monitoring and control efforts.We tested suspected case samples for DENV nucleic acid and IgM antibodies,and analyzed the positive cases.Nucleic acid positive samples underwent DENV-targeted capture and whole-genome sequencing,followed by phylogenetic,homology,and mutation analyses.A total of 84 cases were positive for DENV nucleic acid,and 4 cases were positive for DENV IgM antibodies.The nucleic acid positive cases included all four serotypes(DENV-1 to 4),among which DENV-1 predominated(52.1％).Whole-genome sequencing yielded 43 complete DENV genome sequences:27 DENV-1 strains(primarily genotype Ⅰ,with some genotype Ⅳ),12 DENV-2 strains(all Cosmopolitan genotype),3 DENV-3 strains(all genotype Ⅲ),and 1 DENV-4 strain(genotype Ⅰ).The nucleotide similarities were 89.7％-99.9％for DENV-1,95.6％-100％for DENV-2,and 88.3％-99％for DENV-3.Mutation analysis revealed variations in key sites such as prM,E,and NS3(435)in some strains.This study revealed that multiple regions in Sichuan Province are under dual pressure from both imported and domestically circulating dengue virus strains.The imported strains originated primarily from Southeast Asian countries and China's Guangdong Province and Yunnan Province,and were subsequently transmitted locally.The imported strains exhibited high genetic di-versity,and mutations were observed at critical amino acid sites.