Avian influenza (also known as bird flu) is caused by influenza A viruses, similar to the virus that causes seasonal influenza (flu) in humans. It spreads mainly among wild water birds but can occasionly spread to humans, although this is rare. It can cause mild to severe illness in birds and other animals.

Be aware of the risk of avian influenza if you are travelling to a country where avian influenza outbreaks in animals are occurring. Prevent infection by avoiding contact with wild birds and animals, washing hands regularly with soap and water and thoroughly cooking poultry and poultry products before eating. If you have been exposed to avian influenza, follow further guidance in the Information for Contacts factsheet.

Last updated: 28 May 2024

What is avian influenza?

Avian influenza, or bird flu, is caused by various strains of influenza A viruses.

Some strains cause no or mild disease in wild birds while others can cause severe disease in poultry, like chickens. Certain strains can infect mammals including seals, livestock, and occasionally humans.

The most well-known strains are H5N1 and H7N9. H5N1 was first detected in 1997 in Hong Kong, it reappeared in 2003 and spread rapidly to birds across Asia, the Middle East, the Americas, Europe and Africa. H7N9 was first identified in 2013 in eastern China. Both H5N1 and H7N9 strains have caused serious infections and deaths in humans.

A variant of H5N1, named clade, causes significant illness and deaths in poultry, wild birds and mammals. It has spread rapidly across all continents except Australia. Human infections are rare and typically occur after close contact with sick birds and livestock. Person-to person transmission has not been reported.

Australia has had a number of small outbreaks of other strains of avian influenza on poultry farms that cause less severe disease in birds, with a small number of mild human infections. These people had close contact with sick birds.

One human case of H5N1 has been recorded in Australia, in a person who had acquired the infection overseas and made a full recovery. As of April 2024, no cases of H7N9 have been detected in Australia.

What are the symptoms of avian influenza in humans?

Most infections are mild or have no symptoms. When they occur, common symptoms are similar to seasonal influenza (flu) and include:

  • fever
  • cough
  • tiredness
  • muscle aches
  • sore throat
  • shortness of breath
  • runny nose
  • headache
  • diarrhoea
  • conjunctivitis.

Severe cases can lead to neurological changes, pneumonia, encephalitis (inflammation of the brain) or death. Symptoms will usually appear between 2 to 10 days following exposure.

If you are unwell after travelling to areas where avian influenza outbreaks occur and have been in close contact with birds or wild animals, tell your doctor so the correct tests can be performed.

How does avian influenza spread?

Avian influenza spreads by direct contact with infected birds or their saliva/faeces. Spread can occur from indirect contact through virus containing droplets or dust

Person-to-person transmission is very rare but can occur when a person does not wear personal protective equipment (PPE) and spends prolonged periods with an infected person.

The risk of human avian influenza infection from consuming animal products from areas with avian influenza is very low.

Who is at most risk of getting avian influenza?

You may be at higher risk of getting avian influenza if you travel to countries with avian influenza and have contact with sick birds and other infected animals.

In countries where avian influenza occurs, people at highest risk of getting avian influenza are those who:

  • work with commercial poultry (chicken or turkey) and/or are in close contact with sick birds that may be infected with avian influenza
  • work with and/or are in close contact with other animal species that can be infected with avian influenza e.g. mammals, particularly if they are unwell
  • are in close contact with a person who is infected with avian influenza.

How can avian influenza be prevented?

Practice the below steps to minimise your risk of infection, especially if you are travelling to areas with avian influenza:

  • avoid wild birds and animals, poultry farms and live bird or animal "wet" markets
  • wash your hands thoroughly with soap and water after handling uncooked poultry products (including meat or eggs). Avoid touching your eyes, nose and mouth after touching these products
  • wash kitchen and cooking utensils thoroughly after handling raw poultry
  • ensure poultry products (such as eggs) are well-cooked or pasteurised before eating.

If you work with poultry, your workplace will have infection control procedures that you must follow. You can also protect yourself by wearing PPE including:

  • P2/N95 masks
  • goggles
  • gloves
  • protective clothing

There is no specific vaccine for avian influenza but the seasonal influenza (flu) vaccination can help prevent co-infection with multiple influenza strains.

How is avian influenza diagnosed?

Swabs from the nose and throat are tested to diagnose avian influenza.

Inform your doctor if you have symptoms and have been in close contact with sick birds or animals in the wild or at work, or have travelled recently to a country or region with avian influenza.

What happens if you have avian influenza?

Healthcare workers must notify the local public health unit (PHU) when they suspect you have avian influenza. The public health unit will contact you to understand how you got the infection, and to determine if any other people may be at risk.

If you are unwell, you should isolate to prevent spreading the virus to others, wear a mask, and practice good hygiene. Your close contacts, for example, people you live with, should monitor for symptoms and may need preventive medicine.

How is avian influenza treated?

Antiviral medicines for human influenza (flu) can also prevent severe illness from avian influenza. Your doctor will provide specific treatment and advice, based on your needs.

Global monitoring of avian influenza

Avian influenza spreads in wild birds, particularly in Europe, North and South America, and Asia. The World Health Organization (WHO) provide regular updates on avian and other influenza strains (including swine flu). Some strains have caused cases of human infection. Regular monitoring helps to track the spread and manage outbreaks.

Read more about avian influenza at the World Health Organization website. You can also view the latest monitoring information and data.

Additional resources

For further information please call your local public health unit on 1300 066 055​​​​​.

Current as at: Tuesday 28 May 2024
Contact page owner: One Health