Poultry farms around the world are culling flocks infected by avian influenza and health authorities are closely monitoring outbreaks and possible bird-to-human infections. 

Australia’s first cases of bird flu, as it’s more commonly known, were reported on five farms in Victoria last week. 

On the same day the first bird infection was reported, officials confirmed the first human case: a two-year-old who had recently returned from India. 

According to the Victorian Department of Health, contact tracing revealed no additional cases, and the risk to others is very low. They emphasised that the bird and human incidents were unrelated. 

The disease continues to be reported in animals and animal products around the world. 

Australian health experts say there’s no need to panic but cannot rule out the avian viruses adapting to infect the human respiratory tract.  

Bird flu is not unknown in Australia. A small number of cases have occurred over the past 15 years, including one low pathogenic strain that infected abattoir workers in 2010. 

State and federal authorities and the poultry industry are working to control the current outbreaks. 

Authorities say the risk of bird-to-human infection is low.  

Professor Raina MacIntyre, who leads the global biosecurity program at the Kirby Institute at the University of New South Wales, says this is due to the way this virus operates. 

“Avian flu viruses are adaptive to birds, and birds have specific receptors in their upper respiratory tract that we do not have. Those viruses only spread easily between birds and between some mammals – not humans,” she said.  

In South America, hundreds of thousands of sea birds have died with the H5N1 variant the suspected cause. Reports indicate the virus is present in Antarctica. 

“Antarctica is a worry for us,” Professor MacIntyre said, “because if the virus is in Antarctica, then there could be flyaways of other birds that could bring it into Australia.” 

She said the United States Food and Drug Administration (FDA) has found fragments of the virus in dairy products for sale in grocery stores. However, none of these samples returned evidence of live virus. 

This is likely down to the pasteurisation process, which kills the virus. 

In Australia, food standards require most milk or milk products being sold commercially to meet pasteurisation requirements. 

Unpasteurised or raw milk, apart from goats’ milk, is restricted from being sold as a food product, though there are exceptions in some states that allow local producers to sell raw milk and cheese under strict circumstances. 

The World Health Organization, as well as centres for disease prevention and control in Europe, the US, and Australia, are not alarmed about the risk of a wider outbreak affecting humans, however health experts have said it’s important to keep an eye on how the virus evolves.

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. 

Poultry workers and other humans who have close contact with sick birds are at risk of infection. This can happen when the virus gets into a person’s eyes, nose, or mouth, or is inhaled.  

You can’t contract it by eating fully cooked poultry or eggs, even in areas with an outbreak of bird flu. 

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 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. 

Symptoms in humans range from mild to severe.  

Some strains of bird flu can cause symptoms like 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 also occur. 

Symptoms may appear up to 10 days following exposure.