Avian influenza outbreaks transmitted by wild birds are a cause for concern — not only because of recent egg shortages in local supermarkets, but because a bird flu variant could potentially cause the next pandemic. This is why Professor Paul Horwood and Professor Graham Burgess from the Australian Institute of Tropical Health and Medicine (AITHM) are keeping a close eye on wild ducks in our local parks.
Australia’s 22 million chickens lay 18 million eggs every day. There are also 2.4 million wild ducks living in Victoria alone, and many more around Australia. As many domestic chickens live in free range conditions, they can come into contact with wild birds, such as ducks, who may be infected with avian influenza.
“There are around 150 different types of influenza, but the ones we're most concerned about are variants of the H5 and H7 strains. These variants can mutate into high pathogenic strains,” Professor Horwood said.
“When they mutate, they can infect commercial poultry and cause 100% mortality. Besides, high pathogenic strains like H5N1 could also have human health implications, with the potential to cause a pandemic.”
Professor Horwood, alongside Adjunct Professor Burgess, has been testing duck faeces for avian influenza for over ten years. “We are part of a surveillance network, the National Avian Influenza Wild Bird (NAIWB) Steering Group, that's organised and funded by Wildlife Health Australia,” Professor Horwood said.
The pair conduct most of their work on the shores of urban lakes around Townsville. “We generally go once a month and collect samples of faeces from all the ducks there. Our target is to get around 100 samples a month and 600 per year.
“The presence of the ducks is very much dictated by how much rain there's been,” Professor Horwood said. “If there's been a lot of rain, inland lakes fill up and the ducks migrate inland. But when there's not much rain, they often come to our lakes in Townsville because these lakes are filled with water year-round.”
The researchers take the samples back to the AITHM lab in Townsville and test them for avian influenza viruses. “During the pandemic, Polymerase Chain Reaction (PCR) tests were used to detect the COVID-19 virus. We do a similar thing with the duck faeces,” Professor Horwood said. “We use a PCR test called ‘TaqMan’ that shows us in real time if the virus is present and how much virus DNA is in our sample.”
Professor Horwood said that the detection rates for avian influenza in North Queensland are very low. “Not including last year, we have had two or three positive samples. Last year, we detected two different viruses on different occasions.”
However, even though ducks may currently not be responsible for the egg shortage in Australia, this is no reason to be complacent. “Over the last two decades, we'd only get one outbreak on poultry farms every three or four years,” he said. “In 2024 alone, there have been outbreaks in seven egg farms in Victoria. I wouldn't say that’s unprecedented, but really quite surprising.
“We need to remain vigilant and continue to collect samples from wild waterbirds throughout Australia, so we can detect new strains early and be better protected from avian influenza.”
This research project has been funded by Wildlife Health Australia since 2010 and is ongoing.