Data as of 4pm AEST, 19 August 2026
#19,300
While HPAI H5N1 reporting from governmental sources have slowed in recent days, overnight the Australian press reported on multiple mass mortality events involving birds in South Australia and Tasmania (see ABC News Bird flu suspected after more than 1,000 birds found dead in SA, more deaths in Tasmania).
According to multiple news sources (see here and here), South Australian Premier Peter Malinauskas addressed the SA parliament (Aug 20th) to announce that more than 1,000 crested terns had died across three mass mortality events on several remote offshore islands.
Additionally there are reports of > 2 dozen dead penguins in Tasmania. While H5N1 has not been confirmed, HPAI is strongly suspected. For now, there are no reports of H5N1 in non-avian wildlife, poultry, or livestock.
While we await further details (and/or confirmation) we've two other sources of background information; an expert commentary from Australia's National Testing laboratory CSIRO, and a series of academic analyses from The Conversation.
First this analysis from CSIRO (h/t Pathfinder on FluTrackers):
Expert Commentary: What do we know about H5 bird flu?
18 AUGUST 2026 4 MIN READ
In June 2026, Australia recorded its first cases of the highly contagious H5 bird flu.
As Australia's national reference laboratory for animal diseases, CSIRO's Australian Centre for Disease Preparedness (ACDP) plays a critical role in protecting Australia's valuable livestock and aquaculture industries and the wider community from infectious diseases such as bird flu.
Scientists at ACDP have been conducting testing and genetic analysis to learn more about exactly which strain of the virus has arrived on our shores, and how it is spreading.
All quotes below are available for use by media. Spokespeople quoted:
- Dr Frank Wong, Senior Research Scientist at CSIRO's Australian Centre for Disease Preparedness. Dr Wong is also a World Organization for Animal Health-designated reference expert on avian influenza
- Dr Matt Neave, Team Leader of Sequencing and Agent Characterisation at CSIRO's ACDP
- Dr Debbie Eagles, Director of CSIRO's ACDP.
What is H5N1 and why is it a concern?
Dr Frank Wong:
For the past 5 or 6 years the world has been affected by a bird flu panzootic. This is what we call a pandemic in animals. In this case, because the virus is an avian virus, it has mostly impacted birds around the world.
The clade 2.3.4.4b lineage of H5N1 is a highly pathogenic bird flu virus that emerged around 2020-2021, first spreading across Europe and then moving on to other continents, including Asia and North America.
Along the way it has caused mass mortalities in both domestic poultry as well as many species of wild bird.
H5N1 has been able to spread rapidly across different continents largely due its ability to be sustained in migratory wild birds, like waterfowl such as ducks and geese.
The genotype that we're talking about for Australia, known as genotype B3.2, arose from reassortment in North America and then spread to South America and the sub-Antarctic islands.
It had a great impact on South American poultry industries as well as wild bird life and marine mammals, so that's why we're concerned about the introduction of the virus to Australia.
What does ACDP's genetic testing show us?
Dr Matt Neave:
Sequencing the virus genome has become really important in disease outbreaks like this one. We're now able to do it much quicker than in the past and can get a whole influenza genome in around 15 to 26 hours.
From the viral genome we are able to determine several important things, including the exact strain of the virus. Another thing we can do is compare that viral genome to other reference sequences in our database or public databases online. This allows us to determine how closely related our Australian cases are to the sub-Antarctic ones, for example.
Our testing shows us that the sequences from the first two cases in Australia were closely related to ones from Heard Island. From the data we have at hand, it appears Heard Island is the most likely source of the Australian infections.
By comparing genetic sequences from virus samples, scientists can trace the relationships between the first Australian H5 bird flu cases and those detected on Heard Island. Credit: Matthew J. Neave et al. Show image description
(Follow link to read the full report).
Although there are now roughly 2 dozen entries, going back to H5N1's arrival in Australia in mid-June, over the past few days these 4 essays have been published.
Published: August 20, 2026
The first wave of bird flu is the worst: what Australia can learn from overseas
Bethany J Hoye, University of Wollongong
The rest of the world has already had to grapple with bird flu – and there are lessons for Australia.
Published: August 18, 2026
More than 5,000 little penguins will be vaxxed against bird flu. How will this protect them?
Julie Old, Western Sydney University
Little penguins are flightless and return at night to the same burrow, making it easier to capture and vaccinate them.
Published: August 17, 2026
From the coasts to the plains, bird flu could threaten not just birds – but their homes
Penny Olsen, Australian National University
From raucous honeyeaters to top predators, Australia’s birds are vital to nature.
Published: August 16, 2026
Is bird flu infecting humans? How would we know?
Allen Cheng, Monash University
Even with bird flu circulating in Australia, the risk to humans is low. But some groups are still at increased risk.

