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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Exotic & Emerging Avian Viral Diseases Research » Research » Publications at this Location » Publication #342366

Research Project: Intervention Strategies to Prevent and Control Disease Outbreaks Caused by Emerging Strains of Avian Influenza Viruses

Location: Exotic & Emerging Avian Viral Diseases Research

Title: Evolution, global spread, and pathogenicity of highly pathogenic avian influenza H5Nx clade 2.3.4.4

Author
item Lee, Dong-hun - Orise Fellow
item Bertran, Kateri - Consultant
item Kwon, Jung-hoon - Konkuk University
item Swayne, David

Submitted to: Journal of Veterinary Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2017
Publication Date: 9/1/2017
Citation: Lee, D., Bertran, K., Kwon, J., Swayne, D.E. 2017. Evolution, global spread, and pathogenicity of highly pathogenic avian influenza H5Nx clade 2.3.4.4. Journal of Veterinary Science. 18(S1):269-280. https://doi.org/10.4142/jvs.2017.18.S1.269.

Interpretive Summary: Unique virus strains of deadly H5 avian influenza (highly pathogenic avian influenza, HPAI) which originated in China (Goose/Guangdong lineage) and have changed over time into four genetically distinct subgroups (A – D) within group 2.3.4.4. Since 2014, HPAI group 2.3.4.4 viruses have spread rapidly worldwide through migratory wild aquatic birds and changed through mixing genes with prevailing local mild (low pathogenicity avian influenza, LPAI) viruses. The Group A viruses caused bird outbreaks during 2014-2015, in Asia, Europe, and North America while Group B viruses caused bird outbreaks in Asia, Europe, and Africa during 2016-2017. Group C viruses originated in China have caused bird outbreaks in South Korea and Japan during winter season of 2016-17, and Group D H5N6 viruses have caused bird outbreaks in China and Vietnam. A wide range of bird species, including wild and domestic waterfowl, domestic poultry, and even zoo birds, have been infected with and/or transmitted the group 2.3.4.4 HPAI viruses.

Technical Abstract: Novel subtypes of Eurasian-origin (Goose/Guangdong lineage) H5 highly pathogenic avian influenza (HPAI) viruses belonging to clade 2.3.4 such as H5N2, H5N5, H5N6, and H5N8 have been identified in China since 2008 and subsequently evolved into four genetically distinct groups (A – D) of clade 2.3.4.4. Since 2014, HPAI clade 2.3.4.4 viruses have spread rapidly worldwide through migratory wild aquatic birds and evolved through reassortment with prevailing local low pathogenicity avian influenza (LPAI) viruses. The Group A H5N8 viruses and its reassortant viruses caused outbreaks in wide geographic regions during 2014-2015, including Asia, Europe, and North America. The novel reassortant Group B H5N8 viruses have also caused outbreaks in Asia, Europe, and Africa during 2016-2017. The novel reassortant Group C H5N6 viruses originated in China have caused outbreaks in South Korea and Japan during winter season of 2016-17. Group D H5N6 viruses have caused outbreaks in China and Vietnam. A wide range of avian species, including wild and domestic waterfowl, domestic poultry, and even zoo birds, seem to be permissive for infection with and/or transmission of clade 2.3.4.4 HPAI viruses. Furthermore, these viruses showed altered pathogenicity in birds as compared to previous H5N1 HPAI viruses.