A deadly pig disease raging in China is bound to spread to other Asian countries, experts warn

SHANGHAI, CHINA—African swine fever (ASF), a deadly virus in pigs and wild boar, continues to spread in China and will almost certainly wreak havoc in other countries in Asia soon. That's the somber conclusion from a meeting of animal health experts organized by the United Nations's Food and Agriculture Organization (FAO) in Bangkok late last week. "It's no longer ‘if’ [spread beyond China] will happen but when, and what we can do collaboratively to prevent and minimize the damage,” FAO Chief Veterinary Officer Juan Lubroth said in a statement issued on Friday, at the end of the 3-day meeting. Veterinary authorities from 12 countries agreed to form a new network to share information and work jointly to control the spread of the disease.

The virus that causes ASF doesn't infect humans, but the most virulent strains are nearly universally fatal for pigs. There is no vaccine and no cure, so controlling the spread of the disease requires destroying all animals on infected farms. The appearance of the virus in China in August—and its inevitable spread—threatens devastating economic losses for farmers and shortages of a vital source of protein for citizens of developing countries, particularly in East and Southeast Asia.

China's agriculture ministry reported a new outbreak while the Bangkok meeting was in progress; the virus has now been found at 18 farms or slaughterhouses in six provinces, according to FAO. The outbreak sites are widely dispersed, indicating that shipments of pork products are spreading the disease; live animals aren't usually shipped over such long distances.

The virus is on the move in Eurasia and Eastern Europe as well. Bulgaria reported its first outbreak to the World Organisation for Animal Health in Paris on 31 August; the virus has also been found in Georgia, Russia, Poland, the Czech Republic, Romania, and Moldova. In Europe, the virus is appearing primarily in backyard pens and its spread likely involves wild boars. (The disease can also be transmitted by ticks.) In China, so far, the virus has appeared at larger commercial operations. If it spreads to traditional farms, it might also jump to wild boars and become endemic in the countryside, says François Roger, an animal epidemiologist at the Agricultural Research Center for International Development in Montpellier, France. The precise risk is unclear as little is known about wild boar populations in China.

In an unrelated development, another pig disease has resurfaced in Japan, where the agriculture ministry has confirmed the country's first outbreak of classical swine fever in 26 years, on a farm in Gifu prefecture in central Japan. Although they have similar names, the viruses carrying ASF and classical swine fever are unrelated. The highly virulent ASF can kill entire herds, whereas the classical swine fever virus is less virulent and less dangerous for older pigs than for piglets; it can also be prevented using vaccines. After a campaign to eliminate the virus, Japan was declared free of classical swine fever in 2007.