A deadly swine disease that’s plagued parts of Africa and Europe is spreading across Asia, infecting millions of pigs and causing unprecedented losses. Hardest hit by African swine fever is China -- home to half the world’s hogs -- where prices of pork, a dietary staple, have soared. And the virus has emerged in at least one new Asian country almost every month this year.

1. What is African swine fever?

A highly contagious viral disease which, in its most virulent form, can be 100% lethal. The virus infects pigs, warthogs, European wild boar, American wild pigs, bush pigs, giant forest hogs and peccaries. There is no vaccine or treatment. It is characterized by high fever, loss of appetite and hemorrhaging on the skin and internal organs. Diarrhea, vomiting, coughing and breathing difficulties are other symptoms. Death comes in two to 10 days on average.

2. Does it threaten human health?

No. Still, the disease can have a significant impact on food security through decreased and lost production, as well as on food safety through the movement of disease-infected carcasses that may not be adequately chilled or frozen, leading to bacterial contamination.

3. How does the virus spread?

Via direct contact with infected animals or ingestion of garbage containing unprocessed infected pig meat or byproducts. The virus is found in all of an infected pig’s body fluids and tissues and can survive in feces for several days, and possibly longer in urine. Animals that recover from the illness can carry the virus for several months. Unprocessed meat must be heated to at least 70 degrees Celsius (158 Fahrenheit) for 30 minutes to render the virus inactive. Analysis of China’s first 21 outbreaks found that feeding pigs swill, or food scraps, was linked to more than 60% of cases. Blood-sucking flies, ticks and other insects possibly spread the virus, as can contaminated premises, vehicles, equipment or clothing. Culling infected animals and imposing strict containment measures are the only tools available to limit its spread.

4. What’s China doing?

Massive culling. China had more than 400 million pigs, but those numbers have fallen by half over the past year, Rabobank said in September. The U.S. Department of Agriculture estimated in July that China’s pig supply will slump this year by almost 183 million head -- more than the entire annual output of the U.S. and Brazil combined. China also has banned transport of live hogs and closed trading markets. In September, Vice Premier Hu Chunhua lambasted regional officials for misleading the government on the scale of the epidemic, and said the supply situation will be “extremely severe” through to the first half of 2020. At least one city started rationing meat.

5. What’s the impact been?

Pig farmers have seen their livelihoods hurt. Wholesale pork prices in China are at a record, driving up beef imports as consumers seek alternatives. Pork is the principal source of dietary protein in China and accounts for about a third of meat expenditure in Vietnam, which is facing pork shortages. (Vietnam has culled more than 4.7 million pigs out of a herd of about 27 million.) The virus has cut soybean purchases by China, the world’s top buyer, and dented world prices and export growth. In eastern Europe, where African swine fever emerged in 2014, but at a much smaller scale, outbreaks are estimated to have caused several billion euros in annual losses. It’s estimated that the introduction of the virus into the U.S. would cost producers more than $4 billion in losses.

6. Hasn’t this happened before?

Similar, but smaller in scale. In 2013, the rotting carcasses of more than 16,000 pigs — some of which were reportedly infected with a virus known as PRRS or blue ear — were found in tributaries of the main river running through Shanghai, threatening the region’s water supply. Millions of small piggeries were closed as part of a nationwide program aimed at shifting pork production to larger, more efficient farms. It resulted in one of the largest culls in history — a reduction in hog numbers equivalent to the disappearance of the entire U.S., Canadian and Mexican pork industries in less than two years. That came after a mysterious virus, later identified as blue ear, killed about 400,000 pigs.

7. How is China planning to recover?

Government measures to restart domestic production include increasing subsides and loans to help hog breeding. China will subsidize expansion of new pig farms, favoring larger operations with more than 1,000 head. Many such farms are planning to integrate their businesses to incorporate breeding, fattening, slaughtering and distribution.

8. Where else has the disease shown up?

It’s endemic, or generally present, in sub-Saharan Africa and the Mediterranean island of Sardinia. Over the past several decades, the disease has emerged, and then been eliminated, in parts of Europe, the Caribbean and Brazil. This year hogs have been infected in Mongolia, Vietnam, Cambodia, North Korea, Laos, Philippines, Myanmar and South Korea. In Europe, outbreaks have been reported in Belgium, Bulgaria, Hungary, Latvia, Moldova, Poland, Romania, Russia, Serbia, Slovakia and Ukraine. In Africa, Zimbabwe and South Africa are tackling the virus. Chinese scientists studying the genetic evolution of the virus have said it closely resembles a pan-Russian strain and were working on vaccines.

9. How are markets reacting?

China’s stock market is predicting that 2019 -- the Year of the Pig -- will bring windfall profits to China’s large publicly owned swine operators. Wens Foodstuffs Group Co., the country’s biggest pig breeder, has climbed 33% as of Sept. 26, while record pork prices have helped make stock in Chinese food producers more expensive than their peers worldwide.

--With assistance from Hannah Dormido.

To contact Bloomberg News staff for this story: Jason Gale in Melbourne at j.gale@bloomberg.net;Niu Shuping in Beijing at nshuping@bloomberg.net

To contact the editors responsible for this story: Anna Kitanaka at akitanaka@bloomberg.net, Grant Clark, Paul Geitner

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