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:
- High-throughput pseudovirus neutralisation maps the antigenic landscape of influenza A/H1N1 viruses 6 hours ago
- Timely vaccine strain selection and genomic surveillance improve evolutionary forecast accuracy of seasonal influenza A/H3N2 6 hours ago
- Evaluation of a Novel Data Source for National Influenza Surveillance: Influenza Hospitalization Data in the National Healthcare Safety Network, United States, September 2021-April 2024 6 hours ago
- Scenarios for pre-pandemic zoonotic influenza preparedness and response 6 hours ago
- Stability of Avian Influenza A(H5N1) Virus in Milk from Infected Cows and Virus-Spiked Milk 1 days ago
[Go Top] [Close Window]


