The pandemic H1N1 flu virus was confirmed in a sample from a hog exhibited at the Minnesota State Fair, the Agriculture Department said on Monday.

It was the first discovery in U.S. hogs.

The discovery does not suggest infection of commercial herds, grown for slaughter, because show pigs and commercial herds are separate components of the swine industry and usually are not commingled, USDA said in a statement.

Samples were taken from Aug. 26-Sept. 1 as part of a research project. Additional samples are being tested.

USDA said last week there was no direct link with an outbreak of H1N1 flu among teenagers housed in a dormitory at the fair at roughly the same time.

Agriculture Secretary Tom Vilsack said the World Organization for Animal Health says there is no reason to restrict trade in pork or pork products.

“People cannot get this flu from eating pork or pork products,” said Vilsack in a statement.

WASHINGTON, Oct 19 (Reuters)