Active surveillance for emerging influenza A viruses – Findings from a One Health study in Vietnam’s live bird markets
Abstract
Objectives: Live bird markets (LBMs) in Asia have often been the source of human infections with avian influenza virus (AIV).
Methods: From July 2021 to August 2023, we employed a One Health approach in conducting periodic surveillance for novel influenza A viruses in five LBMs in northern Vietnam. Specimens were studied with egg culture, molecular assays, Sanger sequencing, and next-generation sequencing.
Results: We studied a total of 688 human, avian, and bioaerosol specimens. Among these, 118 (17.2%) were found to have molecular evidence of AIVs. Next-generation sequencing of 92 isolates revealed multiple AIV subtypes, including H4N6 (n=1), H5N1 (n=3), H5N8 (n=6), H6N2 (n=3), H6N6 (n=18), and H9N2 (n=61) and mix infections (n=7). Our H5Nx sequences belonged to the Eurasian lineage clade 2.3.4.4b, while our H6N2 sequences were of group III, H6N6 of group II, and H9N2 of the BJ94-lineage clade 4.6.14.
Conclusions: The relatively high prevalence of AIV, particularly highly pathogenic H5N1 and H5N8 viruses, along with the subtype diversity, frequent co-infections and notable mutations, highlights the urgent need for continued monitoring and control of AIV in Vietnam’s poultry farms and LBMs.
Citation
Vuong N. Bui, Oguzie, J.U., Tung D. Dao, Anh N. Bui, Son D. Tran, Quy D. Nguyen, Hung Q. Nguyen, Trujillo-Vargas, C.M., Marushchak, L.V., Thang Nguyen-Tien, Shittu, I., Hung Nguyen-Viet, Phuc Duc Pham, Huy C. Nguyen, Brooks, J.S. and Gray, G.C. 2025. Active surveillance for emerging influenza A viruses – Findings from a One Health study in Vietnam’s live bird markets. International Journal of Infectious Diseases 108132.
