Agriculture Secretary Tom Vilsack said in a statement that USDA officials have begun to reach out to U.S. trade partners and international organizations to emphasize that H1N1, also known as swine flu, cannot be contracted by eating pork products.
"We have fully engaged our trading partners to remind them ... that there is no scientific basis to restrict trade in pork and pork products," Vilsack said. "People cannot get this flu from eating pork or pork products. Pork is safe to eat."
The USDA's National Veterinary Services Laboratories confirmed the presence of H1N1 after an initial test suggested that as many as three pigs may have had the virus. USDA is continuing to conduct tests to confirm other potential positive tests from the pig samples.
The original samples were taken as a part of a university research project from pigs shown at the Minnesota State Fair between Aug. 26. and Sept. 1.
USDA officials have said that the pigs did not show signs of sickness, and officials suggested they likely contracted the virus from some of the nearly 1.8 million people who visited the fair.
Officials also said the infection of a so-called show pig doesn't indicate an infection of commercial herds because show pigs are in separate segments of agriculture than the swine industry.
Agriculture officials have expected H1N1 to find its way to domestic pigs this year. Herd infections were already reported in Canada, Australia, Argentina, Ireland, the United Kingdom and Norway. A hog vaccine for the virus is being developed but isn't yet available.