Avian influenza (AI) is a highly contagious, viral disease of birds.
All commercial, domestic, and wild bird species can be infected by AI. There are many subtypes or strains of AI. Strains known as low pathogenicity avian influenza (LPAI), can cause a range of symptoms from none to mild flu-like symptoms in wild birds, and mild symptoms in domestic poultry.
Strains known as high pathogenicity avian influenza (HPAI) are very contagious and deadly, causing severe disease and death in both wild and domestic birds. Since 2020, a new strain of HPAI, H5N1 clade H5 2.3.4.4b, emerged and has spread throughout most of the world, resulting in significant disease and deaths in wild birds, as well as some marine mammals.
Why is an outbreak of avian influenza serious in Australia?
Avian influenza (AI) is highly contagious, and an outbreak of high pathogenicity avian influenza (HPAI) strain could cause severe disease and massive deaths in bird populations. The international HPAI strain H5N1 has caused serious and repeated disease events in domestic poultry, wild birds, and some mammals. These events have resulted in significant economic losses for poultry producers and consumers, as well as serious environmental impacts to wild bird populations, including rare and threatened animal species.
AI does pose a human health risk. On rare occasions the virus can be transmitted to humans that are handling HPAI infected birds.
How is avian influenza spread?
The most common way that AI spreads is through direct bird-to-bird contact. The virus is present in bird secretions including faeces, nasal and eye discharge, and blood. Susceptible birds become infected when they come in contact with infected birds or infected bird secretions.
AI can also be spread through indirect contact when uninfected birds are exposed to virus-contaminated materials. Susceptible birds are infected by drinking water or eating foods contaminated by the secretions of infected birds. The disease can also spread through contact with infected animal bedding, egg crates, and other contaminated farm equipment.
People can also spread the disease to different bird populations, by wearing contaminated footwear or clothing, or using contaminated farm equipment around susceptible birds.
Preventing susceptible birds from having contact with infected birds, or viral contaminated materials, is very important for preventing transmission of AI. This can be achieved by preventing wild birds from contacting domestic birds’ water and food sources.
Is HPAI present in Australia?
High pathogenicity avian influenza (HPAI) strain H5N1 clade H5 2.3.4.4b, is not currently present in Australia, but as of late 2023 has spread throughout Africa, Asia, the Americas, and Europe.
While HPAI is not currently in Australia the virus can be introduced through migrating wild birds. The virus can also emerge through the mutation of one of the many low pathogenicity avian influenza (LPAI) strains currently in circulation. LPAI viruses are regularly detected in wild birds in Australia. These are generally harmless and are present worldwide wherever wild waterfowl (ducks, geese, and swans) reside. HPAI can emerge from a mutation of LPAI, and this type of outbreak does occur sporadically in Australia, requiring rapid emergency responses by government and industry. For this reason, commercial poultry producers must keep wild birds out of their sheds and bird enclosures, to prevent contamination of feed and water, and minimize direct bird-to-bird contact between domestic and wild birds.
Surveillance for AI among both wild and domestic birds, is continually performed in Australia and Tasmania, to ensure risk assessments are up to date. For the latest information on any current outbreaks of AI in Australia visit the Australian Government’s website:
National pest & disease outbreaks.
What is the likelihood of the HPAI avian influenza virus entering Australia and causing disease?
The normal hosts of AI do not usually migrate to Australia. Wild waterfowl (ducks, geese, and swans) have spread the high pathogenicity avian influenza (HPAI) strains H5 and H7 across the Africa, Asia, the Americas, and Europe. The birds that typically migrate to Australia are not the normal hosts or spreaders of HPAI strains H5 and H7. Concerningly, the international HPAI strain H5N1 variant is considered to be a high risk of entering Australia via migratory birds compared with previous strains.
There is a risk that a locally circulating low pathogenicity avian influenza (LPAI) strain will mutate and become a highly contagious and deadly HPAI strain.
Australia's strict biosecurity measures are aimed at preventing the disease being transported to Australia by means other than wild birds.
How close is avian influenza to Australia?
Outbreaks of HPAI occur intermittently, often on a seasonal basis, throughout the world. For the latest information on these HPAI outbreaks, go to the website of the World Organisation for Animal Health (OIE). The current international HPAI strain H5N1 clade H5 2.3.4.4b has spread to most continents of the world but has not yet reached Australia or Tasmania.
There has never been an AI outbreak in Tasmanian poultry. LPAI strains of avian influenza have been detected in wild birds in Tasmania, but these detections were not associated with outbreaks of the disease. Animal disease outbreaks of HPAI have occurred on mainland Australia in recent years. To date, each incident was eradicated before the disease could spread widely. There were no reported cases of human health problems associated with any of these outbreaks.
For the latest information on any current outbreaks of AI in Australia visit the Australian Government’s website
National pest & disease outbreaks.
How would Australia cope with an outbreak of avian influenza in poultry?
Australia is well prepared to deal with a case of AI in domestic poultry. Early detection, good surveillance, and rapid response have enabled every outbreak of HPAI in Australia to be quickly controlled and eradicated. No people have become sick during any of these outbreaks.
Planning, preparedness, and response procedures for HPAI continue to be refined and improved at both national and state levels. If HPAI were detected in Australia, the disease would be controlled through a nationally agreed policy, which may include interventions such as farm quarantine, animal euthanasia, and enhanced biosecurity requirements. Australia's eradication plans include personal protection and treatment measures to protect people working on infected properties and other people at risk of infection with the virus.
The recent global circulation of HPAI viruses poses unprecedented risks for vulnerable wildlife species. Animal, human, and environmental health authorities in Australia and Tasmania are preparing to respond to an outbreak of HPAI that causes severe disease in wildlife.
What safety measures are in place to prevent avian influenza entering Australia?
The spread of HPAI strain H5N1 clade H5 2.3.4.4b to multiple continents means that there a higher risk the virus will be introduced into Australia with the return of migratory birds, particularly during late winter through summer.
Commonwealth and state departments rapidly investigate all suspected avian influenza reports. Staff from Commonwealth, State and Territory departments are prepared to rapidly detect, isolate, and control any exotic disease outbreak.
Apart from wild bird entry, Biosecurity Australia has strict guidelines for the importation of all live animals and/or animal products to protect Australia from exotic disease threats. Screening methods include physical inspection, x-ray machines, and detector dog inspections. Officials routinely screen all international flights for animals or animal products, including eggs, egg products, poultry meat, poultry vaccines, feathers, and similar items. International mail is also routinely screened for eggs and egg products.
A nationwide toll-free Emergency Animal Disease Hotline 1800 675 888 operates 24 hours a day for reporting and investigation of any potential AI outbreaks.
What can the broader community do to help reduce the risk of avian influenza?
It's important that oversea visitors and residents returning to Australia do not bring potentially infected material into the country. Potentially infected material includes any items which contain bird meat or bird by-products including bird feathers, skins, eggs, bedding or nesting materials. Biosecurity Australia officers are on high alert as part of the national effort to prevent AI from entering Australia and they will inspect for bird and bird-related products.
For more information on biosecurity restrictions for international travellers, importers and exporters, please visit the Australian Government's website:
Biosecurity in Australia.
Does NRE Tas do any AI surveillance in wild birds?
Surveillance to detect any HPAI virus in wild birds is an important part of rapid detection and prevention. The Commonwealth Government funds state surveillance, which includes collecting swabs from ducks that are shot during the duck season or shot/trapped at any time for crop protection.
Members of the public should report wild bird mortality events to the Emergency Animal Disease Hotline (toll-free) on 1800 675 888.
Can anything be done to stop the spread of avian influenza in wild birds?
Wild waterfowl are known to be the natural reservoir of AI viruses. The
World Health Organisation, the
Food and Agriculture Organisation of the United Nations, and the
World Organisation for Animal Health (WOAH) have come to the consensus that control of AI infection in wild bird populations is not feasible and should not be attempted.
What is the risk of other animals being infected by avian influenza virus?
There is worldwide evidence that the AI virus can infect a range of non-human mammals including pigs, cats, mink, seals, and whales. This list is expected to change over time as the virus adapts to other animals.
A small number of cats including both domestic cats and larger cats in zoos, have been infected with AI virus after exposure to infected birds. In some countries affected by AI, cat owners are advised to ensure that contact between cats and wild birds or poultry is avoided.
For further information