Animal influenza viruses continuously circulate in their reservoirs in nature and pose severe threat to human and animal; therefore, understanding and control of animal influenza viruses will have important implication to public health and social economy.  In this special focus of “Animal influenza virus”, we have one review and five research articles that cover the development of new diagnostic method, surveillance, pathogenicity, and host response to influenza viruses.  

The article by Zou et?al. (2019) reviewed the role and significance of microRNAs (miRNAs) in the pathogenesis influenza virus infection and discussed the potential application of miRNAs.  The article by Shi et?al. (2019) reported the development of a novel loop-mediated isothermal amplification (RT-LAMP) method to detect and identify different subtype influenza viruses.  The article by Sun et?al. (2019) reported the surveillance of swine influenza virus in Shandong Province of China and identification of a novel H1N1 swine influenza reassortant.  The article by Tan et?al. (2019) analyzed the variation of HA proteins of naturally isolated H9N2 viruses and evaluated the function of the potential N-linked glycosylation sites on viral pathogenicity in mice.  The study by Wang et?al. (2019) explored the possible molecular mechanism of duck 2´-5´-oligoadenylate synthetase like protein (dOASL) in response to H5N1 virus infection.  The last article by Huang et?al. (2019) performed transcriptomic analysis of the brain and spleen of ducks that infected with different H5N1 viruses and suggested that H5N1 viruses may escape or subvert host immune response by affecting translation of different immune genes.

The findings reported in these papers will enrich our knowledge on influenza virus infection and provide important information in the prevention and control of influenza.