Now all pork slaughtering and processing plants will need to conduct a virus blood test before they ship products to market.
The latest outbreak is at the largest hog-farming operation so far.
There have been more than 90 outbreaks, many of them in herds of only a few pigs, since the first case in August.
There is world-wide concern about the situation in China because this is a deadly disease that has no cure and no vaccine for prevention. It does not harm humans.
