Bisset AT, Hoyne GF. An Outbreak of Highly Pathogenic Avian Influenza (H7N7) in Australia and the Potential for Novel Influenza A Viruses to Emerge. Microorganisms. 2021 Jul 31;9(8):1639
In 2020, several geographically isolated farms in Victoria, Australia, experienced an outbreak of highly pathogenic avian influenza (HPAI) virus H7N7 and low pathogenic avian influenza (LPAI) viruses H5N2 and H7N6. Effective containment and control measures ensured the eradication of these viruses but the event culminated in substantial loss of livestock and significant economic impact. The avian HPAI H7N7 virus generally does not infect humans; however, evidence shows the ocular pathway presents a favourable tissue tropism for human infection. Through antigenic drift, mutations in the H7N7 viral genome may increase virulence and pathogenicity in humans. The Victorian outbreak also detected LPAI H7N6 in emus at a commercial farm. Novel influenza A viruses can emerge by mixing different viral strains in a host susceptible to avian and human influenza strains. Studies show that emus are susceptible to infections from a wide range of influenza viral subtypes, including H5N1 and the pandemic H1N1. The emu´s internal organs and tissues express abundant cell surface sialic acid receptors that favour the attachment of avian and human influenza viruses, increasing the potential for internal genetic reassortment and the emergence of novel influenza A viruses. This review summarises the historical context of H7N7 in Australia, considers the potential for increased virulence and pathogenesis through mutations and draws attention to the emu as potentially an unrecognised viral mixing vessel.
See Also:
Latest articles in those days:
- [preprint]The mammalian-adaptive PB2-E627K substitution preserves viral fitness of clade 2.3.4.4b H5N1 HPAIV in birds 4 hours ago
- Mallard super-shedders of avian influenza exhibit distinct cloacal microbial abundance profiles 8 hours ago
- A digitally immune-optimized influenza vaccine broadly neutralizes swine and human H1N1 influenza viruses and protects from heterologous challenge 8 hours ago
- Associations between vaccine misinformation and influenza vaccine uptake: a population-based interrupted time-series study in China 9 hours ago
- Infection and transmission dynamics of bovine and human influenza A H5N1 viruses in mouse and hamster models 9 hours ago
[Go Top] [Close Window]


