Factsheet

Avian influenza ("bird flu")

Avian influenza is primarily a disease of birds. Overseas, humans have rarely been infected after close contact with infected birds. To prevent infection, avoid contact with birds and their droppings in affected countries.

Last updated: 29 April 2011

What is avian influenza (bird flu)?

Avian influenza refers to influenza A viruses usually found in birds. Influenza A viruses infect a broad range of avian species and many other species, including humans, pigs, and horses. The H5N1 virus is one strain of avian influenza.

There are many different strains of avian influenza virus but only a few cause severe disease in poultry and other birds, and even fewer cause infections in humans.
In late 2003, poultry outbreaks of the H5N1 virus were identified in several countries in Asia, and have since been reported from many parts of Asia, the Middle-East, Europe and Africa.
The H5N1 virus can rarely also cause severe infections in humans. By the end of 2010 there had been over 500 human cases of H5N1 reported worldwide, with a death rate of over 60 percent.
Public health authorities are concerned that an H5N1 virus may undergo changes that allow it to spread easily between humans, causing a severe pandemic.
Australia has previously had five outbreaks of avian influenza in poultry, all related to H7 viruses, with the last in 1997. Australia has never had the H5N1 virus identified in poultry or humans.

What are the symptoms?

Human infection with avian influenza viruses has caused illness ranging from mild to severe.

Symptoms in humans generally appear between 2 and 7 days after exposure.
People infected with the H5N1 virus have had symptoms ranging from an influenza-like illness (fever, headache, cough, sore throat, and muscle aches) to more severe complications such as pneumonia (infection of the lungs), encephalitis (inflammation of the brain) and other life-threatening complications. Diarrhoea has also been common.

How is it spread?

Almost all human cases of avian influenza infection are known to have occurred in areas where poultry outbreaks have been identified. Transmission of the virus has been through close contact with infected poultry, contaminated surfaces, or contaminated materials such as bird droppings or feathers.

Poultry products (chicken meat and eggs) that have been properly cooked are safe to consume.
The H5N1 virus very rarely spreads from one person to another, but there has been no evidence of sustained transmission among humans in any community.

Who is at risk?

People are at risk of infection if they come in contact with infected birds, their products or their secretions while in affected areas of the world. There is also a small risk of infection for those caring for a person with the human form of the disease.
Australians intending to travel to avian influenza affected areas should discuss the risk of avian influenza with their doctor as part of their routine pre-travel health checks.

How is it prevented?

People travelling to areas affected by avian influenza are likely to have only a very small risk of infection. This risk can be reduced further by:

avoiding places where there may be contact with infected birds, particularly live bird markets
washing hands thoroughly after any contact with birds, their faeces or body fluids
ensuring all uncooked poultry and eggs are handled hygienically during food preparation, with careful attention to hand washing after handling.
ensuring all poultry and eggs are cooked thoroughly before eating

People caring for patients with avian influenza should always:

use appropriate personal protective equipment (PPE) - including P2 masks, goggles, gloves and protective outer clothing;
practise strict infection prevention and control.

People working with poultry and other birds at risk of avian influenza should follow the advice in the publication Health Advice: Interim guidelines for persons working with poultry and other birds at risk of highly pathogenic avian influenza, prepared by the Communicable Diseases Network of Australia at: www.health.gov.au/internet/main/publishing.nsf/content/avian-influenza-poultry-guidelines.htm

Influenza antiviral medicines and vaccines:

A doctor may recommend that people known to have been exposed to an outbreak of avian influenza take a preventive influenza antiviral medicine to reduce their risk of infection.
Travellers intending to live in areas affected by H5N1 avian influenza for an extended period should consider, as a precautionary measure, having access to influenza antiviral medicine. Medical advice should be sought before these medicines are taken.
Seasonal influenza vaccines do not protect against H5N1 influenza infection and are unlikely to protect against other avian influenza strains.

How is it diagnosed?

Avian influenza infection in humans is usually confirmed by testing swabs taken from the nose and throat.

How is it treated?

Specific influenza antiviral medicines used to treat seasonal human influenza infections are expected be effective against avian influenza in humans, including the H5N1 strain, but should be taken within 48 hours of onset of the illness.
Intensive medical care is often required for H5N1 infections, and patients are cared for in isolation to reduce the risk of spread.

What is the public health response?

Doctors and laboratories must notify their local public health unit by phone when they diagnose someone with a suspected or confirmed avian influenza infection.
The local public health unit will work with the patient, the treating doctors, and the laboratory to confirm the diagnosis and take appropriate public health action.
The Australian Quarantine and Inspection Service (AQIS) conducts surveillance for the illegal importation of birds or bird products at Australian borders.
Experts from around the world continue to monitor for potential changes to avian influenza viruses, particularly H5N1, which may indicate that it is able to spread more easily from person to person.