Lv Tiegang, Chen Jie, Li Huafeng, Chen Xiaoyan, Zhang Na, Ma Chunling, Zhang Yanli, You Pengfei
Children's Emergency Department, Women and Children's Health Care Hospital of Linyi, Linyi City, 276000, Shandong Province, China.
Linyi Key Laboratory of Birth Defects Prevention and Control, Women and Children's Health Care Hospital of Linyi, Linyi City, 276000, Shandong Province, China.
Sci Rep. 2024 Dec 4;14(1):30164. doi: 10.1038/s41598-024-81542-4.
Following the relaxation of control measures for COVID-19 in China in December 2022, there was a resurgence of influenza A among children in Linyi. This research aims to analyze the epidemiology and genetic characteristics of influenza A viruses circulating among children in Linyi from April 2022 to March 2024. Throat swab specimens were collected from children with influenza-like illness (ILI), and the types of influenza were identified. The hemagglutinin (HA) genes of influenza A viruses were amplified using reverse transcription-polymerase chain reaction (RT-PCR) and then sequenced. Subsequently, the gene characteristics and phylogenetics of these sequences were analyzed. A total of 6258 cases of influenza A were tested from 54,926 children with ILI over two years, showing three epidemic waves: one in summer 2022 and two in spring and winter 2023. The epidemic waves in summer 2022 and winter 2023 were caused by influenza A(H3N2) viruses. In spring 2023, influenza A(H1N1)pdm09 viruses accounted for 77.1% and A(H3N2) viruses accounted for 22.9%, respectively. The influenza A(H1N1)pdm09 viruses belonged to clade 6B.1A.5a.2a, while the influenza A(H3N2) viruses evolved from clade 3C.2a1b.2a.1a to 3C.2a1b.2a.2a.3a.1. Compared with the vaccine strain of the Northern Hemisphere of the current year, multiple amino acid substitutions and glycosylation sites changes were observed in the HA protein that most likely resulted in antigenic drift. The influenza A viruses have been circulating and evolving persistently in Linyi from 2022 to 2024. Continuous surveillance is essential for comprehending the dynamics of influenza in the post-COVID-19 era.
2022年12月中国新冠疫情防控措施放宽后，临沂市儿童中甲型流感有所反弹。本研究旨在分析2022年4月至2024年3月在临沂市儿童中传播的甲型流感病毒的流行病学和基因特征。从流感样疾病（ILI）患儿中采集咽拭子标本，鉴定流感类型。使用逆转录聚合酶链反应（RT-PCR）扩增甲型流感病毒的血凝素（HA）基因，然后进行测序。随后，分析这些序列的基因特征和系统发育。在两年内，从54926例ILI患儿中共检测到6258例甲型流感病例，呈现出三个流行波：一个在2022年夏季，两个在2023年春季和冬季。2022年夏季和2023年冬季的流行波是由甲型（H3N2）流感病毒引起的。2023年春季，甲型（H1N1）pdm09流感病毒占77.1%，甲型（H3N2）流感病毒占22.9%。甲型（H1N1）pdm09流感病毒属于6B.1A.5a.2a分支，而甲型（H3N2）流感病毒从3C.2a1b.2a.1a分支进化到3C.2a1b.2a.2a.3a.1。与当年北半球的疫苗株相比，在HA蛋白中观察到多个氨基酸替换和糖基化位点变化，这很可能导致了抗原漂移。2022年至2024年，甲型流感病毒一直在临沂市持续传播和进化。持续监测对于了解新冠后时代流感的动态至关重要。
