At a glance
- Seasonal influenza vaccine is available – read more about prevention
- Nationally notifiable disease
About bird flu
Bird flu (avian influenza) is caused by specific influenza A viruses that usually infect birds. These viruses are different to those that cause seasonal flu in people.
Bird flu rarely spreads to people. When it does, it most often causes a respiratory infection.
The current risk of bird flu to people in Australia is considered low.
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Virus types and subtypes
Bird flu in humans is an acute respiratory infection caused by influenza A viruses that usually infect birds.
Like all influenza A viruses, bird flu viruses are classified into subtypes by 2 surface proteins:
- haemagglutinin (H)
- neuraminidase (N).
Virus subtypes – for example, H5N1 and H7N9 – are formed through different combinations of these surface proteins.
Each subtype differs in its ability to spread and cause disease. Five bird flu subtypes (H5, H6, H7, H9 and H10) are known to infect people.
Most reported infections in people are caused by:
- H5N1
- H5N6
- H7N7
- H7N9
- H9N2.
Genetic classifications
Bird flu viruses are further classified into genetic subgroups called clades (clades and subclades are based on the haemagglutinin component) and genotypes (the genotype takes account of all the genetic segments of the virus), which help track:
- viral evolution
- geographic spread
- changes in disease severity.
Pathogenicity in poultry
Bird flu viruses are also classified by severity of disease (pathogenicity) in poultry, as either:
- high pathogenicity avian influenza (HPAI)
- low pathogenicity avian influenza (LPAI).
HPAI and LPAI viruses can cause severe disease in people.
Natural reservoirs
Water birds – such as waterfowl, gulls and shorebirds – are the main natural reservoir for bird flu viruses.
Why it matters to public health
Bird flu is a public health priority.
Infections in people are rare but can cause severe disease or death.
Spread between people is very rare.
Bird flu viruses can change quickly. The more they spread in animals or people, the more chances they have to change.
If bird flu changes in a way that makes it spread more easily between people, it could cause an outbreak or spread more widely. It could also change in ways that cause more serious illness in people.
Large bird flu outbreaks in animals can be distressing and can have social and emotional wellbeing impacts on people.
Bird flu may also affect Aboriginal and Torres Strait Islander peoples through impacts on connection to Country and culturally significant practices that support wellbeing and community life. Aboriginal and Torres Strait peoples also hold valuable knowledge and leadership that can strengthen bird flu responses.
Because of its potential impact, we work with colleagues across multiple sectors to support a coordinated One Health approach to protect against bird flu.
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Global epidemiology of bird flu in people
Bird flu infections in people are detected sporadically across the world. Spread between people is rare, with the last documented cases of person-to-person transmission reported overseas in 2007 (H5N1) and 2016 (H7N9).
Severe disease and death are most commonly reported in:
- H5N1
- H5N6
- H7N9.
Australian epidemiology of bird flu in people
In Australia in 2010, 7 abattoir workers who handled chickens from a commercial poultry farm with an outbreak of LPAI H10N7 reported conjunctivitis and mild upper respiratory symptoms. Two of these workers tested positive to H10N7.
In 2024, Australia reported its first human infection caused by H5N1. The person was infected with clade 2.3.2.1a while travelling overseas and made a full recovery. There were no additional cases in Australia.
Global spread of H5N1 clade 2.3.4.4b in animals
Since 2020, a global animal outbreak of this clade has caused illness and high mortality in:
- poultry
- wild birds
- some mammal species.
In June 2026, H5N1 clade 2.3.4.4b was detected in wild seabirds in Australia for the first time.
Global epidemiology of H5N1 clade 2.3.4.4b in people
Around 100 human infections with this clade have been reported, including more than 70 cases in the United States during 2024 and 2025. Most infections reported during this period were mild, but a very small number of people developed severe disease.
Most cases have been linked to exposure to infected poultry or, among dairy workers in the United States only, infected dairy cattle.
There has been no reported spread from person to person for this clade.
The viruses which caused these infections are genomically different to the viruses that were first detected in birds in Australia in June 2026.
Australian epidemiology of H5N1 clade 2.3.4.4b in people
There have been no human infections of this clade in Australia.
Symptoms
If you’re looking for advice about your own health or treatment options, see healthdirect or speak with a qualified healthcare professional. Our role is to provide public health advice – information and guidance that helps prevent disease, protect communities and improve wellbeing at a population level.
Some infected people have no symptoms at all. But symptoms can include:
- fever
- cough
- sore throat
- runny nose
- conjunctivitis
- muscle aches and pains
- headache
- fatigue
- gastrointestinal symptoms such as nausea, vomiting or diarrhoea (less common).
Symptoms can range from mild to severe.
Serious complications include:
- pneumonia
- acute respiratory distress
- brain inflammation
- sepsis.
healthdirect’s symptom checker can help you decide whether to see a health professional.
Onset of symptoms
Symptoms usually start about 3 to 5 days after being infected, but this can range from 1 to 10 days.
How it spreads
Infected animals shed the virus in secretions, faeces and other body fluids, and into the air.
People can become infected if they:
- touch an infected animal, their body fluids or something contaminated with the virus, and then touch their eyes, nose or mouth
- breathe in contaminated dust or air.
Infection usually happens after close contact with infected poultry – such as, chickens, ducks, turkeys, geese – or contaminated environments.
It is safe to eat properly handled, prepared and cooked meat and eggs.
It’s very rare for bird flu to spread from person to person.
Infectious period
People with bird flu are considered infectious from one day before symptoms start until either:
- 7 days after symptoms begin
- acute symptoms are gone (if symptoms remain after 7 days).
Prevention
Vaccination
Getting an annual flu vaccination is recommended for all people older than 6 months.
Vaccination is especially important for people at greater risk of exposure, as well as people who work with or care for pigs.
The annual flu vaccine does not protect against bird flu but prevents people becoming sick with both seasonal and bird flu viruses at the same time.
Other prevention steps
The best way to protect against bird flu is to stay away from sick or dead birds and wildlife and their:
- surroundings
- droppings
- body fluids
- feathers
- eggs.
Other simple measures to prevent bird flu include:
- washing your hands thoroughly before and immediately after handling any bird or wildlife (even if healthy)
- not allowing pets to touch or eat sick and dead birds or wildlife
- thoroughly cooking meat and eggs before eating.
If you get symptoms within 10 days of contact with sick or dead birds or wildlife:
- call your health professional and tell them you have been around birds or wildlife
- follow your health professional’s advice and take steps to prevent viral respiratory illnesses.
If travelling
If you are travelling overseas:
- stay away from sick or dead animals (especially poultry) and places they are in, including
- poultry farms and backyard chicken enclosures
- areas with free ranging poultry
- live animal ‘wet’ markets
- only eat thoroughly cooked animal products, including meat and eggs
- do not consume raw (unpasteurised) milk
- regularly check the health advice on Smartraveller.
Priority groups and settings
People at greater risk of severe disease
Because there are so few human infections and so many subtypes of bird flu, we do not yet fully know which groups are at greater risk of severe disease.
We expect they are similar to those for seasonal flu, and might include:
- babies and children under 5 years old
- older people
- pregnant people
- Aboriginal and Torres Strait Islander peoples
- people with certain chronic conditions
- people who are immunocompromised
- people who smoke.
If you are at greater risk, it is especially important to take steps to protect yourself.
People at greater risk of exposure
Anyone who spends time around poultry, other birds or wildlife is at higher risk of exposure to bird flu. The risk is much greater if the animals are sick.
Those at highest risk include:
- commercial poultry workers
- animal disease outbreak responders
- veterinarians, veterinarian nurses and veterinary students
- wildlife carers
- laboratory workers handling bird flu specimens.
Read more about protecting your employees or yourself.
Diagnosis and treatment
Bird flu is usually diagnosed through laboratory testing of a sample collected with a swab from the nose or throat.
People with conjunctivitis might have a swab taken from their eye.
Some people might be referred for blood tests to identify previous infection for surveillance purposes.
Rapid antigens tests are not recommended if bird flu is suspected. These tests are less accurate and prevent subtype detection.
Make sure you tell your healthcare professional if you have had contact with birds or wildlife in the past 10 days.
You can use healthdirect’s directory to find a health service near you.
Most people with bird flu receive antiviral treatment to prevent severe disease.
Read more about:
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Some avian influenza viruses that pose a risk to people, including HPAI H5N1, are classified as Security Sensitive Biological Agents (SSBAs) because they meet specific criteria for ‘highly pathogenic influenza virus, infecting humans’. Mandatory regulatory requirements, including reporting, apply when handling confirmed or suspected SSBAs.
Read more about the Security Sensitive Biological Agent Regulatory Scheme.
Surveillance and reporting
Australia takes a One Health approach to surveillance of bird flu.
Influenza A virus (including bird flu) in birds and pigs is nationally notifiable, and animal health authorities work with multiple sectors to monitor bird flu in poultry and wildlife.
Bird flu in humans is a nationally notifiable disease – these are diseases that present a risk to public health.
Health authorities in each state and territory report new human cases through the National Notifiable Diseases Surveillance System.
This is part of national surveillance activities to monitor case numbers around the country and understand disease patterns.
The CDNA National plan for the surveillance of avian influenza for human health provides a framework to detect and monitor bird flu in people in Australia.
Outbreaks
Bird flu outbreaks in poultry require a public health response to reduce the risk of infection in people. Depending on the risk to people, outbreaks in other animals may also require public health action.
Actions public health authorities might take include:
- identifying and managing people exposed to infected animals
- educating people about how to protect themselves and others
- working with animal health authorities and affected industries
- advising about extra infection prevention and control precautions – such as personal protective equipment
- encouraging annual flu vaccination for people who may come into contact with sick or dead birds and wildlife.
Read more about:
- the Department of Agriculture, Forestry and Fisheries H5 bird flu response
- the public health response to bird flu in Australia
- how the Australian Government defines and plans for outbreaks and pandemics.
Support
For more information see:
- toolkit for protecting yourself from bird flu
- resources about bird flu in different languages and formats
- the Australian Government H5 bird flu webpage
- the Australian Government animal outbreaks web page
- CDNA national guidelines to protect bird and wildlife workers
- Food Standards Australia New Zealand information about avian influenza and food safety.
For information about bird flu in your state or territory see:
- Australian Capital Territory
- New South Wales
- Northern Territory
- Queensland
- South Australia
- Tasmania
- Victoria
- Western Australia.
If you need mental health support, see a list of organisations, websites and services that offer support, counselling and information.
For travel advice, see Smartraveller.