Australia’s Minister for Agriculture has notified Australians that overnight laboratory testing confirmed the presence of A/H5N1 in one sick bird and an H5 virus in another, both found in the same region of Western Australia.

Agriculture, not Health?

Why is Australia seeing the Minister for Agriculture fronting up to update us on the “bird flu” arrival? Most likely because no human infections are involved. This is just about two infected birds. And mainly because the Minister for Agriculture, Fisheries and Forestry includes biosecurity, animal diseases and avian and marine animals.

Where were the birds found?

According to a nicely detailed article in The Guardian, two unwell birds – a brown skua (since deceased) and a giant petrel (since deceased) – were found last Sunday at Cape Le Grand National Park in southern WA.

UPDATE: the second bird initially tested positive for H5 avian influenza at the Western Australian Department of Primary Industries and Regional Development’s laboratory and was subsequently confirmed as A/H5N1 on the 22nd at CSIRO’s Australian Centre for Disease Preparedness (ACDP), where the first infection was confirmed.

The A/H5N1 virus is a strain of the species of influenza A virus

The latest influenza naming scheme is shown in the second image below. Like our seasonal influenza viruses A/H3N2 and A/H1N1, A/H5N1 belongs to the genus Alphainfluenzavirus, a subtype of the species Alphainfluenzavirus influenzae. The A/H5N1 detected in each bird will likely be variants of the same strain of A/H5N1.

We have yet to see any publicly available genetic sequence data for variants of this strain, but the sequence has since been added to the GISAID database, from which details require you to sign away one of your children (see image under Updates section below). Its unique identifier is EPI_ISL_20479340. It has already been publicly announced by various outlets that this virus belongs in the A/H5N1 2.3.4.4b. I can’t offer further description.

Naming viruses is complex. I’ve adapted the Ebola virus naming scheme to make it a bit easier to understand how we describe the influenza A viruses, of which there are many. I’m not showing influenza B, C or D viruses here.

The key message

Stay away and don’t touch sick or unwell birds.

The Australian Government has been planning a range of responses to the arrival of A/H5N1. With more testing and more coastal observations, the picture will become clearer.

For now, there are no human cases in Australia, and in the nearly seven decades of this subtype’s known existence on Earth, there have been just under 1,000 human cases, of whom just under half died.

Human infections are, as far as we know, fairly rare and are driven by close contact with infected animals. Let’s hope it stays rare, as it is easy to steer clear of birds that are clearly unwell (and the many other species this virus can infect). The fewer chances we give the subtype to mix with our seasonal influenza viruses, the better!

References

• https://www.directory.gov.au/portfolios/agriculture-fisheries-and-forestry
• https://www.theguardian.com/australia-news/2026/jun/20/australia-confirms-first-case-of-h5n1-bird-flu
• https://www.agriculture.gov.au/campaigns/birdflu#h5_detection
• https://minister.agriculture.gov.au/collins/media-release/media-release-confirmed-H5-bird-flu-australia-beth-cookson
• https://www.abc.net.au/news/2026-06-22/second-case-of-deadly-h5-bird-flu-confirmed-in-wa/106827752
• https://www.dpird.wa.gov.au/research/laboratory-and-research-facilities/
• The first case of H5N1 bird flu in Australia has been confirmed. What does this mean?
  https://theconversation.com/the-first-case-of-h5n1-bird-flu-in-australia-has-been-confirmed-what-does-this-mean-285712

Updates

• 24JUN2026. Corrected that the second bird had not yet been confirmed. It has subsequently been confirmed. Also, the first bird’s genome sequence has been added to GISAID; however, describing it or analysing it is too convoluted a process for me to bother with (see GISAID rules below).