Avian influenza

Current Situation

Agriculture Victoria (AgVic) is responding to the detection of highly pathogenic avian influenza (H7) avian influenza in two poultry operations near Meredith and in the Terang region.

This detection is not the more severe H5 HPAI strain that has resulted in significant outbreaks globally in recent months. Australia remains the only continent free of this strain of avian influenza.

AgVic is working with the poultry operations to eradicate the disease, in accordance with nationally agreed AUSVETPLAN response strategies and guidance from the national Consultative Committee for Emergency Animal Diseases. Details of the response can be found on the AgVic webpage.

Additionally, DPIRD is managing a detection of low pathogenic H9N2 avian influenza in a small-scale poultry operation in the Southwest of Western Australia.

This is not connected to the situation in Victoria. H9 strains of avian influenza are known to occur in wild bird populations including in WA, which is the most likely source of introduction to this property. 

DPIRD has been working with the affected poultry operation to manage the detection and to prevent re-infection from wild birds.

Avian influenza overview

Large outbreaks of high pathogenicity avian influenza (HPAI) (H5N1 clade 2.3.4.4b) overseas have been causing significant mortalities in poultry and wild bird populations in recent years.

The risk of HPAI being introduced to Australia through migratory birds’ annual flight paths has historically been considered to be low; however the current global situation means the risk is now considered higher than in previous years. The period of greatest concern in Australia is September to November, when migratory birds return from the northern hemisphere  of Australia.

The H5N1 clade 2.3.4.4b is a high pathogenicity strain of avian influenza currently circulating globally, impacting not only commercial poultry but also an extended range of wild birds and wild mammals.  As at 21 May 2024, this strain has not been detected in Australia.

Avian influenza is regularly detected in wild waterbirds throughout the world, including Australia. Wild water birds are considered the natural host of the virus and do not frequently show symptoms of infection. Sometimes the virus spills over from wild birds into domestic birds and may cause disease. The virus can also mutate to become highly pathogenic if it comes into contact with non-waterbird species, particularly poultry. Depending on the strain, the virus causes a wide range of signs in poultry from high mortality to no obvious signs.

Avian influenza strains are classified as either high pathogenicity or low pathogenicity.

Highly pathogenic avian influenza (HPAI) causes sudden, severe disease and very high death rates in birds.

Low pathogenic avian influenza (LPAI) may cause some deaths in birds and reduce production. It may cause mild signs such as slight facial swelling or nasal discharge, coughing or sneezing, or birds may not show any signs of infection.

Do we have avian influenza in Australia?

There have been previous outbreaks of highly pathogenic avian influenza in commercial poultry in recent years, in other states/territories. All outbreaks were eradicated. None of these outbreaks involved the globally circulating H5N1 clade 2.3.4.4b strain. The source of each outbreak is thought to be water or feed contaminated by wild birds.

DPIRD carries out surveillance of waterbirds  for avian influenza, which shows that low pathogenic avian influenza does circulate in wild waterbirds in Western Australia without the birds showing signs of disease.

Low pathogenic avian influenza has occasionally occurred within farmed birds/poultry in Australia, including within Western Australia, and has been quickly controlled under control and eradication programs.

What are the signs of avian influenza?

Signs can vary with the species affected, bird age, the virus strain and the bird’s environment.

Signs of severe highly pathogenic avian influenza:

• sudden death of large numbers of birds without warning signs.

Signs of less severe highly pathogenic avian influenza:

• depression
• reduced food intake
• weakness
• soft-shelled eggs
• reduced egg laying
• dark, thickened or drooping combs and wattles
• diarrhoea
• coughing
• difficulty breathing
• increased deaths.

 Signs of low pathogenic avian influenza:

• depression
• reduced food intake
• reduced laying
• nasal discharge, coughing, sneezing
• diarrhoea
• increased deaths.

Why should I report avian influenza signs?

Avian influenza is a reportable disease. If you see signs of avian influenza in birds, you are legally required to report it to DPIRD.

The earlier the disease is detected, the faster it can be eradicated. If you delay reporting the disease, it will spread to other birds.

How do I report avian influenza signs?

If you see any of the signs of avian influenza in your birds or wild birds, call:

• your private vet, or
• your local DPIRD veterinary officer, or
• the Emergency Animal Disease hotline on 1800 675 888.

Contacts for DPIRD vets are available on the webpage Livestock Biosecurity contacts.

How does avian influenza spread?

Wild waterbirds are the natural reservoir of avian influenza viruses. Infected birds spread the virus through their faeces, saliva and nasal secretions.

Domestic birds can be infected with avian influenza by:

• direct contact with an infected bird
• contamination of water or food by infected birds
• contact with people, equipment, vehicles, shoes or clothing contaminated by infected birds.

What is the treatment for avian influenza?

There is no treatment for avian influenza in birds.

How can I reduce the risk of avian influenza occurring in my birds?

The following simple biosecurity measures can help prevent disease outbreaks:

• reduce the likelihood of your poultry/birds having any contact with wild birds
• ensure your birds’ water supply is not contaminated by wild birds or other animal waste or is otherwise treated to inactivate avian influenza Water from rain, dams or rivers should be chlorinated before use
• ensure feed is not contaminated by wild birds or other animal waste
• control rodents
• quarantine new birds/poultry
• limit visitors to your birds/poultry. Ensure visitors have clean clothing and footwear,
• restrict employees from having contact with any birds outside of work
• keep equipment and poultry housing
• locate poultry sheds and aviaries away from wild waterbirds
• wash hands before and after handling birds.

See the comprehensive bird biosecurity guidelines and National Farm Biosecurity Manual - Poultry Production - DAFF (agriculture.gov.au) on the federal Department of Agriculture and Water Resources website for more information.

DPIRD veterinary contacts

See the Livestock Biosecurity contacts webpage for contact details of your nearest DPIRD Field Vet.