TY - JOUR AU - Lu, Jing AU - Raghwani, Jayna AU - Pryce, Rhys AU - Bowden, Thomas AU - Thézé, Julien AU - Huang, Shanqian AU - Song, Yingchao AU - Zou, Lirong AU - Liang, Lijun AU - Bai, Ru AU - Jing, Yi AU - Zhou, Pingping AU - Kang, Min AU - Yi, Lina AU - Wu, Jie AU - Pybus, Oliver AU - Ke, Changwen T1 - Molecular Evolution, Diversity, and Adaptation of Influenza A(H7N9) Viruses in China T2 - Emerging Infectious Disease journal PY - 2018 VL - 24 IS - 10 SP - 1795 SN - 1080-6059 AB - The substantial increase in prevalence and emergence of antigenically divergent or highly pathogenic influenza A(H7N9) viruses during 2016–17 raises concerns about the epizootic potential of these viruses. We investigated the evolution and adaptation of H7N9 viruses by analyzing available data and newly generated virus sequences isolated in Guangdong Province, China, during 2015–2017. Phylogenetic analyses showed that circulating H7N9 viruses belong to distinct lineages with differing spatial distributions. Hemagglutination inhibition assays performed on serum samples from patients infected with these viruses identified 3 antigenic clusters for 16 strains of different virus lineages. We used ancestral sequence reconstruction to identify parallel amino acid changes on multiple separate lineages. We inferred that mutations in hemagglutinin occur primarily at sites involved in receptor recognition or antigenicity. Our results indicate that highly pathogenic strains likely emerged from viruses circulating in eastern Guangdong Province during March 2016 and are associated with a high rate of adaptive molecular evolution. KW - avian influenza KW - avian influenza virus KW - viruses KW - influenza KW - H7N9 KW - phylogenetics KW - molecular evolution KW - molecular epidemiology KW - adaptation KW - diversity KW - respiratory infections KW - China KW - virus subtypes KW - hemagglutination inhibition assay DO - 10.3201/eid2410.171063 UR - https://wwwnc.cdc.gov/eid/article/24/10/17-1063_article ER - End of Reference