Sydney - Middle East Times Int’l: When Victorian health officials confirmed Australia's first human case of avian influenza last week, there were a few key details that struck some of those listening as odd.

The announcement came on the same day that the state's agriculture department reported an outbreak of bird flu at a poultry farm near Meredith. But the Department of Health made clear that the two incidents were totally unrelated.

In fact, the human case, a two-year-old who had recently returned from India, had been detected in early March. One of Australia's leading epidemiologists, Professor Raina MacIntyre, noted the almost three-month delay in reporting the case was "not ideal".

The source of the human infection was also somewhat mysterious. Health officials confirmed the child had picked up the highly pathogenic virus while travelling in India, but did not note any close contact with sick animals or other infected humans.

Two further outbreaks on Australian poultry farms followed, prompting hundreds of thousands of chickens to be culled, while deadly strains of bird flu continued to wreak havoc on the US dairy industry and wild animal populations around the world.

There is an unsettling, familiar tone to all of this news, and a quiet hum of concern runs beneath it — could avian influenza erupt into the next pandemic?

Some of the world's foremost experts in infectious disease and public health governance say while it is not time to panic, there is a reasonable risk that we must be prepared for. 

"What we worry about is those avian viruses mutating to pick up an adaptation to the human respiratory tract. That's how a human pandemic would emerge," Professor MacIntyre said.

These experts share a concern that the fatigue and divisiveness wrought out by the COVID-19 pandemic present significant challenges in tackling new outbreaks head on — already they are hampering efforts to test, report and contain the outbreak in the US. 

They also believe we're closer to another pandemic than many people realise — but we have "a golden opportunity" to prepare now and get it right.

First, it's helpful to understand how different outbreaks of bird flu are categorised. 

Avian influenza is an infectious disease that spreads predominantly among wild birds and poultry. Just like human influenza, there are several types of avian influenza viruses — these are classed broadly as either high pathogenic or low pathogenic, indicating how sick they make infected birds.

As with other infectious diseases like COVID-19, avian influenza viruses are divided into subtypes or "strains" and then further into clades. These subtle differences occur as the virus evolves and mutates to work around host cells' defences. Some adaptations can lead to "spillover" events, where the virus passes from one species to another to infect other animals and, in rarer cases, humans.

On May 24, a second avian outbreak was confirmed at another Victorian poultry farm in Terang, which had commercial links with the farm in Meredith. Testing confirmed this outbreak was another H7 strain, known as H7N9.

A third outbreak was confirmed last week at a mixed poultry farm in Western Australia – a low pathogenic H9N2 strain not connected to the Victorian outbreaks.

State and federal authorities are working with affected industries to control the poultry outbreaks, with the infected farms under quarantine and orders for free-range and backyard flocks within restricted areas to be temporarily housed.

The risk of human transmission of avian flu viruses is relatively low – it's generally picked up where there has been close contact with infected animals. Health authorities around the world are urging caution among people working in affected industries such as poultry and dairy, or other jobs handling wild animals, but overall, the risk to the general public is considered low.

Professor MacIntyre, who leads the global biosecurity program at the Kirby Institute at 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. 

But that could change if the virus has opportunities to pick up adaptations that allow it to enter the human respiratory tract. 

Professor MacIntyre notes that avian influenza has already crossed over from animals that have traditionally carried the virus — waterfowl including ducks, geese and swans — into other wild birds and even mammals.

"We've seen mass die-off of sea lions and seals, red foxes, coyotes, squirrels … and we're now seeing it in 130 other wild birds that were never hosts for spreading this virus before," she said.

In South America, hundreds of thousands of sea birds have died including more than 40 per cent of Peruvian pelicans. Scores of Adelie penguins and skuas have died in "mass mortality events" across Antarctica, with H5N1 the suspected cause.

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

For the moment, the World Health Organization, as well as centres for disease prevention and control in Europe, the US and Australia, doesn't appear to be alarmed about the risk of a wider outbreak or pandemic affecting humans. In its latest weekly update, the WHO wrote:

"Whenever avian influenza viruses are circulating in poultry, there is a risk for sporadic infection and small clusters of human cases due to exposure to infected poultry or contaminated environments … The zoonotic threat remains elevated due to the spread of the viruses among birds. However, the overall pandemic risk associated with A(H5) is considered not significantly changed in comparison to previous years."

However, as several public health and infectious disease experts have warned in the past few years, the question of another pandemic is not so much a matter of if, but when.

Professor Kelley Lee has been studying the governance of global pandemics for years, and most recently her work with the Pandemics & Borders international research group has been reflecting on the response to the COVID-19 pandemic and strengthen strategies for future outbreaks. 

Broadly, her work aims to answer the question: is the world prepared for another pandemic?

"I would say the short answer is no, we're not anywhere near prepared. And indeed, in some ways, I think we're worse prepared than we were prior to COVID-19," she said.

Professor Lee says the biggest lesson from the COVID-19 pandemic has been how global collaboration was instrumental in managing the spread and science the virus — from identifying SARS-CoV-2 as a novel pathogen, to developing vaccines and potential drug treatments.

And conversely, where coordination was lacking, it slowed down the world's ability to bring the virus under control. One example was the varied approaches to imposing travel restrictions and border controls, which her research has shown came at huge economic and societal cost.

Professor MacIntyre says for Australian authorities working to contain the current poultry outbreaks, the most urgent priority should be considering financial measures to make robust testing and reporting as straightforward as possible.

"The biggest thing that can be done is financial compensation for farmers. Without that, there's not going to as much testing and reporting as there should be, and outbreaks won't be disclosed," she said.

Dr Adalja is similarly focused on managing the outbreaks in livestock industries well. He says a lack of trust in public health officials is a fundamental issue to solve for efficient and thorough testing and surveillance. Involving veterinarians with established relationships in the industry is among some of the suggestions to work around this. 

Outside of encouraging stringent testing in these industries, Professor MacIntyre says the other sign to watch out for will be mass die-offs of birds or other wild animals.

And while the current local outbreaks don't pose an immediate risk of human transmission, it's a possibility she says we need to be prepared for.

"In terms of the human pandemic, it's a problem for everybody. If a pandemic arises in the US or Europe, it's going to end up here. So it's in our interest to be closely monitoring for that."