A deadly swine disease is spreading across northeastern China, infecting hundreds of animals and threatening the world’s largest pig industry. African swine fever killed 340 pigs in Leqing city in Zhejiang, the Ministry of Agriculture and Rural Affairs said Thursday, marking the fourth Chinese province to confirm cases of the incurable disease in August. Outbreaks have been reported as far as 1,200 kilometers (746 miles) apart.
1. What is African swine fever?
A highly contagious viral disease which, in its most virulent form, can be 100 percent lethal to domestic pigs and wild boars. There is no vaccine. It is characterized by high fever, loss of appetite, hemorrhages in the skin and internal organs, with death coming in 2-10 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?
Pork is the country’s principal source of dietary protein. Further spread could lead to significant culling of animals, hurting the livelihoods of pig producers, cutting pork production, pushing prices higher and driving consumers to other sources of protein. There may also be major repercussions on international trade as a result of import bans. In the Europe Union, where African swine fever emerged in 2014, outbreaks have spread across the region at a rate of about 200 kilometers a year, causing an estimated several billion euros in annual losses.
4. Where else has the disease shown up?
It’s endemic, or generally present, in sub-Saharan Africa. Over the past several decades, the disease has emerged, and then been eliminated, in parts of Europe, the Caribbean and Brazil. More recently, it’s been found in at least seven EU countries and has caused outbreaks in Russia, Ukraine and Moldova this year. In West Africa, an outbreak in five districts of central Ghana was reported in May. In China, the Veterinary Bureau has reported infections in Zhengzhou, Henan; Lianyungang, Jiangsu; Shenyang, Liaoning as well as Leqing city. Chinese scientists studying the genetic evolution of the virus have said it closely resembles a pan-Russian strain.
5. How has China dealt with past disease 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 in 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.
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 degrees Fahrenheit) for 30 minutes to inactivate the virus. 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.