On Saturday, a suspected case of deadly [H5 bird flu], also known as high pathogenicity avian influenza (HPAI) H5N1, was confirmed in a brown skua.

This large seabird was found in Cape Le Grand National Park near Esperance, about 700 kilometres south-east of Perth in Western Australia.

The virus is also suspected to have affected another seabird, a southern giant petrel, found at the same area.

Following the initial testing, samples collected from these birds were sent to the CSIRO to confirm the first Australian cases of H5N1, specifically the clade 2.3.4.4b H5N1 lineage. Avian influenza viruses are categorised by subtype (creating the H and N number combination, here H5N1) and specific clades within the H5 subtype.

This virus has devastated wildlife populations in other continents, and this could be the start of a long push to protect Australian birds and wildlife in Australia.

Where did this virus come from?

Avian influenza viruses, of which HPAI H5N1 is just one kind, have been around for millenia. In the vast majority of cases they cause no disease in birds. These strains are referred to as low pathogenicity avian influenza viruses.

However, in 1996 one of these viruses evolved to become disease causing, and since then, this HPAI H5N1 has caused severe disease in poultry, and has become endemic in poultry. With........

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