A man in laboratory clothing, including protective eyewear and gloves, holding a syringe above a tray of eggs, in a laboratory.

CSIRO avian virologist, Mr Paul Selleck, testing for the avian influenza within the high-biocontainment area of the Australian Animal Health Laboratory in Geelong, Victoria.

What is avian flu?

Find out what avian influenza is and how CSIRO is research is helping to fight it.

  • 20 November 2006 | Updated 14 October 2011

What is avian influenza?

Avian influenza (AI) is a natural infection of many species of wild water birds. Usually it causes disease only in domestic poultry. To date, all outbreaks of the highly pathogenic form have been caused by H5 and H7 strains of influenza A, in particular the H5N1 strain.

AI has infected some humans, most of whom have been in direct contact with sick or dead poultry.

There have been approximately 150 human deaths from the H5N1 strain worldwide, from 258 confirmed cases. While there has been occasional virus transmission between people there has been no sustained transmission of the virus between people

How is it spread?

H5N1 multiplies in the respiratory tract and bowel of infected birds. Nasal fluids, saliva and droppings contain large amounts of virus that is infectious to birds and occasionally to people. The disease is spread among poultry by the movement of infected birds or by movement of infected materials.

The disease is a human health concern because viruses can change over time to create strains with different properties. A strain could develop that was readily transmissible from human to human and to which we would have little or no immunity. Such a strain could infect many people.


The current strategy for preventing this virus from spreading and endangering humans is to cull infected poultry in farms and markets in affected areas. Prevention of infection is being attempted by large scale vaccination in countries where the disease has become established.

Australia has several lines of protection including:

  • quarantine to keep infected materials out of the country
  • biosecurity measures on farms to prevent poultry infection
  • early reporting and effective, rapid response to any outbreaks.

The biocontainment facilities at CSIRO’s Australian Animal Health Laboratory (AAHL) play an important role in diagnosing AI in Australia and throughout south-east Asia. They are also used to test the effectiveness of vaccines and antiviral drugs for Australian and overseas clients.

The Australian Government is funding the development of vaccines to protect humans against this strain of virus. However, development of these vaccines is only in the early stages.


CSIRO has been at the forefront of providing an effective treatment for the H5N1 strain of influenza.

In the 1990s CSIRO research discovered the structure of a protein, neuraminidase, that is essential for the replication of all flu virus strains.

A drug, called Zanamavir, was designed to inhibit this protein. It was designed with the help of the Victorian College of Pharmacy and approved for use in 1999. It was developed by Australian biotechnology company Biota Holdings Ltd and marketed by pharmaceutical company GlaxoSmithKline as Relenza™.

In 2004, CSIRO laboratory experiments found that Relenza™ is effective in the inhibition of AI.

'If the disease does mutate into a form which can be passed from human to human it is important to know we already have a treatment available,' said CSIRO’s Dr McKimm-Breschkin.

Relenza™ is available on prescription and is being employed globally for prevention and cure.

Find out more about Avian influenza activities at CSIRO’s Australian Animal Health Laboratory.

CSIRO receives a royalty stream from the sale of Relenza™

  • Relenza™ is a trademark of GlaxoSmithKline.