A deadly swine disease is spreading across eastern Asia, infecting millions of pigs and threatening the world’s largest hog industry. Since emerging in China in August 2018, African swine fever has been detected in the Philippines, Mongolia, Vietnam, Laos, Cambodia, Myanmar and North Korea.

1. What is African swine fever?

A highly contagious viral disease which, in its most virulent form, can be 100% lethal to domestic pigs and wild boars. There is no vaccine. It is characterized by high fever, loss of appetite and hemorrhages in the skin and internal organs. Death comes in two to 10 days on average. Diarrhea, vomiting, coughing and breathing difficulties are other symptoms.

2. Does it threaten human health?

No. The virus infects pigs, warthogs, European wild boar, American wild pigs, bush pigs, giant forest hogs and peccaries. 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. Culling infected animals and imposing strict containment measures are the only tools available to limit further spread.

3. What’s the concern?

Economics and trade. China has more than 400 million pigs, or over half the world’s swine, Vietnam has about 27 million and the Philippines about 13 million. Pork is the principal source of dietary protein in China and accounts for about a third of meat expenditure in Vietnam. The culling of pigs to stem the disease’s spread, along with restrictions on the movement of animals, has hurt the livelihoods of pig producers, cut pork production and pushed consumer prices higher. Almost 5 million pigs in Asia have now died or been culled because of the disease, or more than 10% of the total pig population in each of China, Vietnam and Mongolia, according to the Food and Agriculture Organization of the United Nations. In eastern Europe, where African swine fever emerged in 2014, outbreaks have spread at a rate of about 200 kilometers a year, causing an estimated 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.

4. 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. 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. In China, the Ministry of Agriculture and Rural Affairs has reported infections across the whole country, including in areas near big cities of Beijing, Shanghai and Tianjin. Vietnam has reported outbreaks in 63 provinces/cities, with more than 4.5 million pigs culled. Chinese scientists studying the genetic evolution of the virus have said it closely resembles a pan-Russian strain and were working on vaccines.

5. How has China dealt with past outbreaks?

When the rotting carcasses of more than 16,000 pigs — some of which were reportedly diseased — were found in early 2013 in the tributaries of the main river running through Shanghai, threatening the region’s water supply, millions of small piggeries were closed. The nationwide program was 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.

6. How does the virus spread?

It’s found in all body fluids and tissues of infected domestic pigs and spreads via direct contact with infected animals or ingestion of garbage containing unprocessed infected pig meat or pig meat products. It 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 between pigs, as can contaminated premises, vehicles, equipment or clothing. Brazilian researchers blamed the outbreak there on trade and tourism.

7. What’s China doing this time round?

It has culled millions of pigs, 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 as domestic pork prices surged.

8. How is China planning to recover?

Recent comments indicate the government is keen to start rebuilding domestic production. Measures 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.

9. How are markets reacting?

The U.S. Department of Agriculture estimated in April a decline in Chinese hog production this year of 134 million head -- equivalent to the entire annual output of American pigs -- and the worst slump since it began counting China’s pigs in the mid 1970s. Wholesale pork prices in China are at record, driving up beef imports as consumers turn to alternatives. The virus has cut soybean purchases by China, the world’s top buyer, and dented world prices and export growth. 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 49% as of Sept. 9, while record pork prices have helped make stock in Chinese food producers more expensive than their peers worldwide.

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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