A disease sweeping through Chinese hog herds is helping negate the effects of the trade war for American farmers, with U.S. pork sales to the Asian nation back to levels before tariffs were introduced.

China was the third-largest buyer of pork in U.S. Department of Agriculture weekly data released Thursday. The 3,300 metric ton-purchase was the most since February, a month before China imposed tariffs on U.S. pork. Hog futures rose 4.4 percent in Chicago, the most in two weeks.

“This is a game changer,” said Dennis Smith, a senior account executive at Archer Financial Services Inc. “It gives confirmation that the disease is far worse than what we’ve been told.”

Outbreaks of African swine fever have been reported at farms in 20 Chinese provinces since August, with about 600,000 hogs culled. But until now, the country has abstained from upping its imports from the U.S.

The U.S. also reported sales of another 9,400 tons to China in 2019.

Some cuts are dirt cheap due to a pileup of domestic supplies, with wholesale loins for example at the lowest price since 2002. “When they see a staple of their diet on sale,” they’re going to start buying it, Smith said.