Rome: Almost 5 million pigs in Asia have now died or been culled because of the spread of African swine fever over the past year, the United Nations Food and Agriculture Organisation said on Friday, warning Asian nations to keep strict control measures in place. ASF has wiped out over 10 per cent of the pig population in China, Vietnam and Mongolia, and is also present in Cambodia, North Korea and Laos, FAO said, citing its latest figures. The contagious viral disease that affects domestic and wild pigs was first detected in Asia one year ago this month. While not dangerous to humans, the disease causes up to 100 per cent fatality in pigs, leading to severe economic losses to the pig sector, FAO said. With FAO support, other countries in the region are ramping up preparedness efforts to prevent further spreading of the disease, the UN agency said. "As there is no commercially available vaccine, we need to place greater emphasis on other disease counter efforts. Countries must be vigilant at borders - land, sea or air - in preventing the disease's entrance and spread through the introduction of infected pigs or contaminated pork products.