The National Pork Producers Council has canceled this year’s World Pork Expo due to concerns about African swine fever spreading in China and elsewhere in Asia. The event was to be held in June at the Iowa State Fairgrounds and typically draws 20,000 people. African swine fever affects only pigs and presents no human health or food safety risks, the council said. There is no vaccine to fight the disease. “While an evaluation by veterinarians and other third-party experts concluded negligible risk associated with holding the event, we have decided to exercise extreme caution,” said NPPC President David Herring.