Genetic characteristics of highly pathogenic H5N8 avian influenza viruses isolated from migratory wild birds in South Korea during 2014-2015

• DOI: 10.1007/s00705-016-2979-4
• Publication Date: 2016-07-16T17:07:01Z
• Authors: Young-Jae Si; Won Suk Choi; Young-Il Kim; In-Won Lee; Hyeok-Il Kwon; Su-Jin Park; Eun-Ha Kim; Se mi Kim; Jin-Jung Kwon; Min-Suk Song; Chul-Joong Kim; Young-Ki Choi
• Keywords: Viral evolution; H5N1 genetic structure

The continuous worldwide spread of highly pathogenic avian influenza (HPAI) H5N8 viruses among wild birds and poultry is a potential threat to public health. In the present study, we investigated the genetic characteristics of recent H5N8 viruses continuously isolated from migratory birds over two winters (2013-2014 and 2014-2015) in South Korea. Genetic and phylogenetic analysis demonstrated that the 2014-2015 HPAI H5N8 viruses are closely related to the 2013-2014 viruses, including virulence markers; however, all eight gene segments of 2014-2015 H5N8 viruses clustered in different phylogenetic branches from 2013-2014 H5N8 viruses, except the A/Em/Korea/W492/2015 virus. The H5N8 viruses of Europe and North America belong to sublineages of the 2013-2014 Korean H5N8 viruses but differ from the 2014-2015 Korean H5N8 viruses. Further hemagglutination inhibition (HI) assay results showed that there were 2-to-4 fold differences in HI titer between 2013-2014 and 2014-2015 H5N8 viruses. Taken together, our results suggested that the 2014-2015 Korean H5N8 viruses were genetically and serologically different from those of 2013-2014 winter season H5N8 viruses, including those from Europe and North America.