When Ebola outbreaks occur, the world watches.

Not so with African swine fever (ASF) despite it being a haemorrhagic disease like Ebola, and despite it killing millions of pigs worldwide.

But as it marches across China, Africa, Asia and Europe, biosecurity experts say there is a real chance it could cross the United States' borders within a year, with the potential to cost that country around $22 billion in the first year alone.

It has already been found in six pork products brought into Australia in January, though they were stopped at airports and mail processing centres, protecting the country's African swine fever free status.

For how long remains questionable, and industry and authorities are imploring travellers to respect the country's biosecurity laws.

Is Australia prepared?

Ever since the outbreaks in Belgium and China last year, Australian authorities have been on high alert and have identified incoming passengers and mail as high-risk areas.

That is exactly where the contaminated items were found in December-January and for the first time, instead of destroying the products, testing was used to confirm the presence of African swine fever.

Australian Pork Limited's (APL) Deb Kerr said while it was not a disease that affected humans, there was big part to play by humans. (It is a different disease from swine influenza.)

"It is a human pandemic because we are largely responsible for the spread of it."

Refrigerated dog food, pork jerky and dried pigs ears are some of the more common potential sources of African swine fever — dirty boots, farm workers and transport are also high risk.

In the case of Belgium, several arrests have occurred over imports of wild boar that are believed to have been brought in for the European hunting season.

China goes high-tech to combat African swine fever spread

The Chinese government is looking to eradicate all backyard farming because that has been the biggest cause of the spread of African swine fever, due to the waste that is fed to those pigs. ( Reuters: Stringer )

In China, African swine fever is a big deal.

As the world's largest producer and consumer of pork it is pulling out all stops to try to stop the spread of the disease, even though just this week two more new outbreaks were confirmed.

Some of the country's larger producers are now turning to technology to try to identify the disease as it begins, right from the first cough.

News agency reports from China say tech giants Alibaba and JD.com are using facial and voice recognition technology to monitor the health of pigs in their stalls, and to track any coughs or changes in behaviour in the animals.

A company called Yingzi Technology is pioneering pig facial recognition, which it claims could "revolutionise" the pork industry.

This is a strategy Australia's pork industry supports, because the technology has the potential to realise the pig is sick long before a farmer would notice.

But while the Chinese government is pushing a high-tech agenda in farming, smaller pig producers and some animal health experts are sceptical of technology's potential to stop a disease like African swine fever in its tracks.

Ms Kerr agreed there were potential limitations, but APL was also keen for technology to develop at the production end so that the virus can be detected in meat.

She said this was really important for African swine fever, as even if a cure was found tomorrow, the virus remained viable in meat — that had been frozen — for three years.

"So it's a risk to the world's pig industry for three years even if it could be stopped tomorrow," she said.

China looks to end backyard pigs

Meat industry analyst Simon Quilty said one of the fallouts from the spread of African swine fever was that Chinese consumers had turned off pork and transitioned to beef.

"Chicken, lamb and mutton has all improved but the importing of beef is about three times more than the next competitor in the protein market," he said.

China is the largest pork consumer and producer in the world and Mr Quilty said the best information to date was that China had culled 950,000 head but their inventory figures suggested its pig population had dropped 5 per cent.

"We do know that 30 per cent of production in China exists in backyards and the government is looking to eradicate all backyard farming because that's been the biggest cause of the spread of African swine fever, because of the waste that is fed to those pigs," he said.

He said there was a culture going back thousands of years, where Chinese people had grown pigs all their lives and they were feeding them in their backyards with waste product.

"Our expectation is, if they eradicate the backyard pig industry, estimated to be 130 million, that is 30 per cent of their entire pig production that will be eradicated, that's 17 per cent of the world production," Mr Quilty said.

"When you start to weigh up all the numbers, you've just seen this massive shortage of protein that's going to evolve over the next five to 10 years."

Denmark builds a pig-proof fence

Countries are going to extreme measures to keep ASF out of their pig populations.

Denmark is building a fence along its border with Germany to keep wild boar from entering the country. ( Supplied: The Danish Nature Agency )

Denmark is in the process of building a 70-kilometre fence from coast to coast along its German border to keep out wild pigs and stop them from spreading the disease to Danish pig farms.

In Denmark pork is big business.

Danish pork exports out of the European Union are worth 1.5 billion euro ($2.4 billion).

As a result Jens Monk Ebbesen from the Danish Agricultural and Food Council said the country's agriculture sector was keen to protect itself from the virus.

"We have very few wild boars in nature, about 100 to 150, and most of them have been migrating from Germany into Denmark in the last 10 years or so," Mr Ebbesen said.

As a result Danish farmers have been allowed to hunt them on their side of the border, but industry believed a fence was necessary for them to be eradicated.

Mr Ebbesen said every time African swine fever made jumps over long distances, for instance from the eastern part of Europe to Czech Republic or the Belgium or to Hungary, it had been humans moving food stuffs and the virus being left where wild boars had picked up those food stuffs and got the virus.

Construction of the 1.5-metre-high mesh fence started earlier this year.

The fence is embedded 50 centimetres under the ground is expected to cost 10 million euro ($15.7 million) and farmers will fund 4 million euro ($6.3 million) of that.

It has been funded by the Danish Government for five years to keep up the maintenance and in the meantime farmers believe all the wild boars on the Danish side of the border can be removed in that time.

Environmentalists have raised concerns though about the disruption the fence could bring to the habitats of other wild animals.

Mr Ebbesen said they were trying to manage that during the construction.

"There will be some small holes for each — 100 metres by 20 centimetres — for small animals such as hares, and deer can jump over," he said.

"The fence will of course have some openings where there are highways or railroads for example.

"And then there will be people crossing with tractors and machinery, because farmers have land on both sides of the border so they have to be able to cross and in these openings we will put up cameras."