South Korea is the latest country to confirm an outbreak of African swine fever (ASF), as the UK government has said it expects the disease to arrive within a year.

In the midst of what has been described as the “largest ever animal disease outbreak”, China announced this week that it was ditching its pork tariffs. China, the largest pork consuming and producing country in the world, has been hit particularly hard by ASF, a disease that is fatal for pigs and extremely contagious.

As many as 100 million pigs have been lost already, according to China’s official declared inventory, said Adam Speck, a senior commodity analyst with IHS Markit’s Agribusiness Intelligence. Rabobank, a financial services company that specialises in food and agriculture, predicted that this year China would lose between 20% and 70% of its herd: potentially as many as 350 million pigs, a quarter of the world’s total. Official figures state that over a million pigs have been culled.

Facebook Twitter Pinterest Blood samples taken from pigs for ASF testing east of Manila. ASF was confirmed in the Philippines on 14 September. Photograph: Rolex dela Peña/EPA

There are reports that pork is being rationed in some parts of the country, and the agriculture ministry confirmed that the rise in the price of pork over the last year had been caused by ASF.

“ASF in China is turning out to be the largest global event for animal protein,” Speck told the Guardian. “The impacts are going to completely change the global trade in animal protein over the next 10 years, and those changes will be permanent. China is home to half the world’s hogs. It is not an exporter of product – they consume half the world’s pork. When you have devastation like the devastation that ASF has released, you reduce the world’s supply. We don’t have enough globally to replace what China has lost.”

Dirk Pfeiffer, a veterinary epidemiologist at City University of Hong Kong and an ASF expert, described the epidemic as “probably the most serious animal health disease [the world has] had for a long time, if not ever”.

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Alistair Driver, editor of the UK’s Pig World, said: “China’s ASF crisis has already had a significant impact on global meat trade.

“The massive hole in pork production has resulted in large volumes of pork being exported to China from all over the world, led by Spain and Germany, and this has contributed to higher pork prices globally, although the impact has barely been felt in the UK.”

The US National Pork Producers Council welcomed the news that the pork tariff would be abandoned. “China is the largest producer and consumer of pork,” a spokesperson told the Guardian. “They’re going to be looking for more reliable sources and there is no more reliable source than the US. This will have a cascading effect around the world.” China has been engaged in a trade war with Donald Trump since January 2018.

In the UK, the government is reported to have set the threat level for ASF to “medium”. The farming minister George Eustice confirmed to the National Pig Association that that meant “an outbreak is expected within a year”.

The outbreak of ASF in South Korea was announced by the agriculture minister on Tuesday. Around 4,000 pigs will be culled and the disease alert level has been raised to the maximum. ASF was confirmed in the Philippines on 14 September.