Data Sheet 1_Molecular epidemiology and genetic characteristics of influenza viruses in a local pediatric population of eastern China, 2024.pdf

IntroductionThe persistent circulation of influenza viruses following the COVID-19 pandemic remains a major public health concern, yet local genomic epidemiology in pediatric populations is not well-defined.
MethodsIn 2024, we collected 490 influenza antigen-positive specimens from a pediatric hospital in Qidong, eastern China, and performed influenza genome enrichment-based whole-genome sequencing, yielding 425 genomes (86.73%) with at least hemagglutinin (HA) and neuraminidase (NA) segments.
ResultsA/H1N1 (45.41%), A/H3N2 (18.35%), and B/Victoria (36.24%) co-circulated, with two activity peaks in January and December. Phylogenetic analysis assigned these viruses to clades 6B.1A.5a.2a (A/H1N1), 3C.2a1b.2a.2a.3a.1 (A/H3N2), and V1A.3a.2 (B/Victoria). Positively selected sites in HA included lineage-specific residues such as position 210 in B/Victoria and positions 187 and 372 in A/H3N2. The oseltamivir resistance marker NA-H275Y was detected in 7/193 (3.65%) A/H1N1 strains, whereas no detected resistance to RNA polymerase inhibitors.
DiscussionThese findings highlight the co-circulation patterns, genetic diversity, and antiviral susceptibility profile of influenza viruses in a pediatric population in eastern China, supporting the importance of sustained genomic surveillance to guide local prevention strategies and clinical management.

引言 新型冠状病毒肺炎（COVID-19）大流行后，流感病毒的持续传播仍是重大公共卫生关切，但儿童群体的本地基因组流行病学特征尚未得到充分阐明。
方法 2024年，我们从中国东部启东的一家儿童专科医院采集了490份流感抗原阳性标本，采用基于流感基因组富集的全基因组测序技术进行检测，最终获得425株（占比86.73%）至少包含血凝素（hemagglutinin, HA）和神经氨酸酶（neuraminidase, NA）片段的流感病毒全基因组序列。
结果 甲型流感病毒A/H1N1亚型（占比45.41%）、A/H3N2亚型（占比18.35%）以及乙型流感病毒B/Victoria系（占比36.24%）共同流行，且存在1月和12月两个活性高峰。系统发育分析显示，这些病毒分别归属于进化分支6B.1A.5a.2a（A/H1N1）、3C.2a1b.2a.2a.3a.1（A/H3N2）以及V1A.3a.2（B/Victoria）。血凝素（HA）蛋白的阳性选择位点包含亚型特异性残基，例如B/Victoria系的210位氨基酸以及A/H3N2亚型的187位和372位氨基酸。在193株A/H1N1毒株中，7株（占比3.65%）检测到奥司他韦耐药标志物NA-H275Y，未检测到对RNA聚合酶抑制剂的耐药性。
讨论 本研究结果阐明了中国东部儿童群体中流感病毒的共同流行模式、遗传多样性以及抗病毒药物敏感性特征，证实了持续开展基因组监测对于指导本地流感防控策略制定与临床诊疗工作的重要意义。