Emergence and dissemination of clade 2.3.4.4 H5Nx influenza viruses—how is the Asian HPAI H5 lineage maintained

• Published in: Current opinion in virology Vol. 16; pp. 158 - 163
• Main Authors: Claes, Filip, Morzaria, Subhash P, Donis, Ruben O
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-02-2016
• Subjects: Animals; Animals, Wild - virology; Asia - epidemiology; Birds; Communicable Diseases, Emerging; Disease Outbreaks; Genotype; Humans; Influenza A virus - classification; Influenza A virus - genetics; Influenza in Birds - epidemiology; Influenza in Birds - transmission; Influenza in Birds - virology; Influenza, Human - epidemiology; Influenza, Human - transmission; Influenza, Human - virology; Reassortant Viruses
• ISSN: 1879-6257; 1879-6265
• DOI: 10.1016/j.coviro.2016.02.005

•A new avian influenza A(H5N1) virus clade (2.3.4.4) is spreading globally in birds.•This virus revealed surprising propensity to reassort with NA subtypes other than N1.•Two subtypes, have spread to countries in Asia (H5N6), Europe and North America (H5N8).•Low virulence in poultry and wild birds may contribute to long range geographic spread.
Highly pathogenic avian influenza (HPAI) A(H5N1) viruses containing the A/goose/Guangdong/96-like (GD/96) HA genes circulated in birds from four continents in the course of 2015 (Jan to Sept). A new HA clade, termed 2.3.4.4, emerged around 2010–2011 in China and revealed a novel propensity to reassort with NA subtypes other than N1, unlike dozens of earlier clades. Two subtypes, H5N6 and H5N8, have spread to countries in Asia (H5N6), Europe and North America (H5N8). Infections by clade 2.3.4.4 viruses are characterized by low virulence in poultry and some wild birds, contributing to wide geographical dissemination of the viruses via poultry trade and wild bird migration.