Influenza A virus continues to circulate among children in Linyi, northern China, after the relaxation of COVID-19 control measures.

Publication date: Dec 04, 2024

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.

Open Access PDF

Concepts Keywords
China Adolescent
Glycosylation Child
Influenza Child, Preschool
Winter Children
China
COVID-19
Epidemiology
Female
Genetic characteristics
Humans
Infant
Influenza A virus
Influenza A virus
Influenza, Human
Male
Phylogeny
SARS-CoV-2
Seasons

Semantics

Type Source Name
drug DRUGBANK Influenza A virus
disease MESH COVID-19
pathway KEGG Influenza A
disease MESH influenza
disease IDO protein
disease MESH death
disease MESH complications
pathway REACTOME Influenza Infection
disease MESH Emergency
disease MESH Birth Defects
drug DRUGBANK Coenzyme M
disease IDO host
disease MESH infection
disease MESH etiology
disease MESH non infectious diseases
disease IDO nucleic acid
drug DRUGBANK Pentaerythritol tetranitrate
drug DRUGBANK L-Asparagine
drug DRUGBANK L-Threonine
drug DRUGBANK Proline
disease MESH virus infection
disease MESH respiratory infections
disease IDO pathogen
disease IDO infectivity
disease MESH Infectious diseases
pathway REACTOME Reproduction

Original Article

(Visited 1 times, 1 visits today)