Bird flu (avian influenza)

Bird flu, also known as avian influenza, is an infectious disease of birds and is caused by several different strains of the bird flu virus. It spreads between both wild and domesticated birds and very rarely spreads from birds to humans. Human cases of bird flu are usually people in close contact with infected poultry or other birds.

There are different strains of bird flu, some that are more likely to cause death and disease in birds (highly pathogenic) and some that are less likely to cause death and disease (low pathogenic).

Overseas, highly pathogenic strains have been causing outbreaks in both wild and domesticated (poultry) birds, and in mammals. Several bird flu outbreaks have previously occurred in Australia among commercial flocks of birds, all of which were contained and eradicated.

How is bird flu spread?

There is no clear evidence that bird flu can be transmitted from human to human. However, this may have happened in rare cases, like when a person has been caring for a sick family member.

Wild birds are believed to be the carriers of bird flu viruses. Migratory birds infected with the virus could potentially spread the bird flu to countries they visit.

Wild birds don’t usually show symptoms of bird flu, although highly pathogenic strains circulating overseas have caused illness and death in some wild birds. Bird flu viruses typically kill domesticated birds, such as chickens and turkeys. There is no evidence that the current circulating highly pathogenic strains of bird flu (e.g. H5N1) can be spread easily from human to human.

Symptoms in sick birds differ depending on the species but can include diarrhoea, breathing difficulties, and death. A sick bird sheds the virus in its feathers, mucous, saliva and faeces.

Who is at risk?

Most people are not at risk of this disease, except if they come in contact with infected birds or their secretions while in affected areas of the world, or possibly if caring for a person infected with the virus.

Humans who have close contact with sick birds are at risk of infection with bird flu, such as poultry workers. This can happen when virus gets into a person’s eyes, nose or mouth, or is inhaled. For example, a person may handle a sick bird, contaminate their hands with chicken poo, and forget to wash their hands before eating. They will then ingest the infected bird faeces.

You can't catch avian influenza through eating fully cooked poultry or eggs, even in areas with an outbreak of bird flu.

How is it prevented?

Be aware of the risk of bird flu if you are travelling to, or living in, a country where outbreaks are occurring in birds or humans. People travelling to areas affected by bird flu should:

• avoid poultry farms and live bird "wet " markets
• avoid contact with wild or domesticated birds
• wash their hands thoroughly after handling birds and uncooked poultry products such as meat or eggs
• ensure that poultry or poultry products are cooked thoroughly before eating.

The seasonal flu vaccine doesn't protect against avian influenza. However, it can help prevent the mixing of bird flu with seasonal flu virus, which can prevent new mutated viruses that could spread rapidly. Vaccination with seasonal influenza vaccine is strongly recommended.

People who are working with infected birds, must use personal protective equipment (including P2 or N95 respirator/mask, goggles, gloves, and protective clothing), follow infection control protocols, and may require anti-viral medication.

What are the symptoms of bird flu?

When people are infected with bird flu, no symptoms, or mild symptoms such as red sore eyes (conjunctivitis) or mild respiratory symptoms are most common. However, some strains of bird flu can cause symptoms similar to severe human flu (fever, cough, tiredness, muscle aches, sore throat, shortness of breath, runny nose, headache). Pneumonia, encephalitis (inflammation of the brain) and diarrhoea may occur.

Symptoms may appear between 1 and 10 days following exposure.

Tell your doctor if you have been to a country where there is bird flu

If you have returned from a country affected by bird flu and feel unwell, it’s important to seek medical advice. Although the risk of becoming infected with bird flu is very low, it’s important that when making an appointment with your healthcare provider, you tell them about any possible exposures to bird flu. Wear a mask and call ahead to make sure you can be isolated from others.

How is it diagnosed?

In humans, bird flu is usually diagnosed by testing swabs taken from the nose and throat.

How is it treated?

Several anti-viral medications used to treat human flu are also effective for bird flu. These can be used if a person developed symptoms after possible exposure to bird flu, or to prevent illness in a person who was in close contact with bird flu.

What is the public health response?

Should human cases be suspected in Victoria, the Local Public Health Unit will work with the patient, the treating doctors, and the laboratory to confirm the diagnosis. Cases will be isolated from others to prevent further infections.

Close contacts of cases will be counselled about the risk of infection. Should they develop symptoms, they will also be advised to isolate and be tested for bird flu.

In Victoria, animal health authorities (Agriculture Victoria) investigate and respond to bird flu outbreaks in poultry farms. When there is an outbreak of bird flu in a poultry farm, people who have been exposed to infected birds are followed up by the Local Public Health Unit to monitor for symptoms.

Where to get help

• In an emergency, always call Triple Zero (000)
• Your GP (doctor)
• NURSE-ON-CALL Tel. 1300 60 60 24 (24 hours, 7 days) - for confidential health advice from a registered nurse
• Find my Local Public Health Unit
• Emergency Animal Diseases, Agriculture Victoria, Victorian Government, Tel. 136 186
• Infectious Diseases: Guidelines and advice, Department of Health, Victorian Government Tel. 1300 651 160