Avian influenza
Avian influenza (AI), also known as 'bird flu', is a virus that causes high numbers of deaths in poultry, wild birds, and some mammals. Occasional infections have been detected in humans.
The virus is classed into 2 types, depending on its severity in poultry:
- low pathogenicity avian influenza (LPAI) – less disease and can readily mutate into HPAI
- high pathogenicity avian influenza (HPAI) – more disease with mortality rates up to 100% possible.
Most birds can become infected and spread the virus to a wide range of species. There is an increased risk of HPAI being introduced to Australia through:
- its rapid global spread
- migratory birds returning to our shores annually.
Low pathogenicity AI strains are unlikely to cause disease in wild birds or other wildlife species, but the H5 and H7 subtypes have the potential to mutate into HPAI forms when introduced to poultry.
Global situation
Since 2021, there have been many detections overseas of HPAI viruses in wild birds, wild mammals, and poultry. HPAI H5N1 clade 2.3.4.4b has been the predominant strain during the past 24 months.
Both individual and mass mortalities have been observed. Based on the latest reporting to the World Organisation for Animal Health (WOAH), the new and ongoing HPAI outbreaks have significantly increased. These are notably causing losses in the sub-Antarctic islands and countries across most continents.
Avian influenza in Australia
Between May and June 2024, outbreaks of the H7 strain of HPAI were declared in Victoria, New South Wales and the Australian Capital Territory. All outbreaks were successfully eradicated.
In February 2025, Agriculture Victoria confirmed the presence of HPAI at poultry properties in northern Victoria. The virus strain is high pathogenicity H7N8, which is different from the strains that impacted Victorian poultry farms during 2024. Importantly, this is not the H5N1 avian influenza strain that is circulating globally. Read more about the current response to avian influenza by Agriculture Victoria.
There are currently no restrictions on the movement of poultry and fertile eggs into SA beyond the normal requirements for poultry movement.
Find updates on the current disease situation in Australia, including state and territory-specific information about how to protect your birds.
Previous detections
Detections of HPAI are rare in Australia. All previous outbreaks have been in poultry – these occurred in other states and were successfully contained and eradicated. HPAI has not been found in poultry in South Australia.
LPAI circulates among wild native birds and is more common in waterfowl (ducks and geese) and shorebirds (waders and sandpipers), both of which are the natural reservoirs of the virus.
Symptoms in birds
Avian influenza can be confused with many other diseases that have similar clinical signs. The infection can vary in severity, including the following:
- sudden death in several birds in a short space of time – typical of HPAI infection
- respiratory distress (open mouth breathing, coughing, sneezing)
- nervous signs (twisted neck, inability to stay upright, inability to fly, uncoordinated movement, walking or swimming in circles, partial or full paralysis)
- swollen head
- reluctance to move, eat, or drink
- reduced egg production
- misshapen eggs
- diarrhoea
- droopy appearance.
AI can be highly infectious, resulting in rapid spread in highly pathogenic forms of the disease.
When to report
Early detection of HPAI is essential for controlling the disease. The following observations must be reported immediately – if unsure, call the hotline for advice about bird mortalities.
| Commercial poultry | Backyard poultry (50 birds or less) | Wild birds and animals |
|---|---|---|
Either:
| Both:
| Any:
|
If you see multiple sick or dead birds:
- Avoid contact with them and keep pets away – don’t touch them.
- Record the date, time, location, species (type of bird), and how many.
- Report your observations to the Emergency Animal Disease Hotline.
Reducing risks
Avian influenza spreads from wild birds to poultry. Even with movement conditions in place to control interstate HPAI detections, SA poultry is at ongoing risk from wild birds in our state.
Good biosecurity is critical at all times to protect poultry flocks from disease.
All poultry owners must have biosecurity plans. Best practice farm hygiene and biosecurity practices are adopted in the Australian poultry industry and are standard practice. National farm biosecurity manuals outline these measures.
There is no vaccination for AI virus for poultry in Australia.
Outbreak preparation
Outbreak preparation
The Biosecurity division of PIRSA works with the National Avian Influenza Wild Bird Surveillance Program, which is coordinated by Wildlife Health Australia.
This program monitors AI virus presence in wild birds to understand the risks and prevent infection in poultry flocks. Disease investigations are also performed in poultry and wild bird mortalities, testing for avian influenza.
If HPAI is detected in Australia, it is declared as an emergency animal disease. Immediate actions will focus on its eradication and minimising the impact of any outbreak.
Learn how government and industry work together to respond to disease outbreaks.
Husbandry and hygiene practices for poultry
Husbandry and hygiene practices for poultry
To achieve a high level of biosecurity, restrict contact between poultry and wild birds. Take these steps to maintain your overall flock’s health:
- Keep feed and water inside sheds where practical, or covered so they are difficult for wild birds to access.
- Make sure fresh feed and water is provided daily.
- Keep feed and water spaces clear of faeces and other organic matter.
- Ensure drinking water is treated, especially if it is straight from a natural water source, such as a river or dam. Treated drinking water should be regularly tested for effectiveness.
- Change nesting materials on a regular basis.
- Minimise the presence of vegetation that attracts wild birds, particularly waterfowl.
- Make sure poultry species are prevented from mixing – keep chickens, ducks and turkeys separate.
- Limit any visitor contact with birds. Check whether essential visitors have recently been at other premises where poultry are kept.
- If you attend poultry shows, don’t allow your birds to mix directly with others.
- Keep new birds separate from your flocks in a quarantine pen for at least 4 weeks, until you are sure they are disease-free after transportation.
Human health
Human health
The spread of avian influenza from birds to people is rare but may occur with some strains of the virus if there is close contact with:
- infected birds or their droppings
- heavily contaminated environments.
Always practise good personal hygiene, including washing your hands thoroughly with soap and water, before and after handling birds and eggs.
People who have regular contact with poultry or other animals at risk of avian influenza are strongly recommended to have the seasonal flu vaccine each year.
If you are experiencing cold or flu symptoms after handling sick birds or poultry, call your doctor for medical advice.
SA Health has more information about avian influenza in humans – including symptoms, treatment and prevention.
More information
- HPAI information – Wildlife Health Australia
- Avian influenza – Department of Agriculture, Fisheries and Forestry
- H5 avian influenza (bird flu) – Department for Environment and Water
- Responding to avian influenza (producer factsheet) – Animal Health Australia
- Control measures for avian influenza (producer factsheet) – Animal Health Australia
- Avian influenza guidelines – Australian Eggs
