Raleigh, N.C. — North Carolina State Fair officials reemphasized Friday that measures are in place to guard against H1N1 after preliminary tests show three pigs in Minnesota may have contracted the virus making them the first potential U.S. cases in swine.

The samples were taken from pigs shown at the Minnesota State Fair between Aug. 26 and Sept. 1 as part of a university research project. Officials expect results next week to confirm whether the pigs were infected with the H1N1 virus, also known as swine flu.

The pigs did not show signs of sickness and officials said they likely contracted the virus from some of the nearly 1.8 million people who visited the fair.

More than 200 pigs are on display at the N.C. State Fair. The Fair set up hand-washing stations around the grounds, especially in areas where visitors are allowed to touch animals, in an effort to prevent the spread of H1N1.

“We feel like they are above industry standards and quite effective in minimizing the risk, so we can continue to have a really good agricultural fair,” State veterinarian Dr. David Marshall said.

While the chance of a pig infecting a person is considered remote, the animals can act as mixing vessels if they happen to catch two different strains at the same time, allowing mutation of a new one. Officials said there's no evidence that's happened.

Still, the news was clearly unwelcome for the state pork industry, which has worked to distance itself from the illness.

“We have seen, across the board, some industry reduction in production, as well as producers reducing their breeding herds, therefore reducing the output of production we will have in the long run,” said Deborah M. Johnson, CEO of the N.C. Pork Council.

Johnson said people should not worry about eating pork.

“Pork is safe to eat. You can not get the H1N1 virus from eating pork,” she said.

Minnesota is the country's No. 3 pork-producing state behind Iowa and North Carolina.