South-east Asia is battling to contain the spread of highly contagious African swine fever, known as pig Ebola", which has already led to the culling of millions of pigs in China and Vietnam. African swine fever, which is harmless to humans but fatal to pigs, was discovered in China in August, where it has caused havoc, leading to more than 1.2m pigs being culled. China is home to almost half of the world's pigs. There is no vaccination for African swine fever, which causes pigs to internally haemorrhage until they die, so the only option to contain the disease is to kill any contaminated animals. Some estimates say that in China up to 200m animals may eventually be slaughtered. The virus can last for several weeks on anything from clothes to vehicles, allowing for it to easily travel long distances. "This is the biggest animal disease outbreak we've ever had on the planet," said Dirk Pfeiffer, a veterinary epidemiologist. Currently the battle to contain the disease is being lost. "There are concerns that the disease will continue to spread across the countries in south-east Asia," said Dr Wantanee Kalpravidh, regional manager for UNFAO, who said they believed the swine fever cases being reported by governments in the region were "underestimates". Wantanee said problems included the lack of compensation for pig farmers in south-east Asia whose herds were culled, giving them little reason to report a disease outbreak, and fears that banning movement of pigs and pork across borders would only create a "black market".