(Bloomberg) — Twelve people were confirmed to have a variant of influenza related to pigs in the past week after coming into contact with the animals, the U.S. Centers for Disease Control and Prevention says.

Ten of the cases of the H3N2v virus occurred in Ohio, where people who had attended a county fair where reportedly ill swine were present, the CDC said in an online report dated Friday. Another case in Indiana also was linked to a county fair, and the final person in Hawaii had direct or indirect contact with an animal, the CDC said.

There is no evidence that the virus can be transmitted through properly handled meat, the CDC said.

The H3N2 variant of the virus contains the M gene of the H1N1 virus that was declared a pandemic in 2009, according to the statement. A total of 29 cases of this variant have been reported since July 2011, of which 19 were associated with fairs where swine were present. In all cases, human patients recovered from the illness, the CDC said.

“Late summer is typically fair season across the United States, and fairs are a setting that can provide many opportunities for exposures to occur between pigs and people,” the CDC said. People should “take recommended precautions when interacting with pigs or their environments, including frequent hand washing and avoiding contact with pigs that appear ill.”

Swine in “a number of U.S. states” have been detected to have the H3N2 variant, and the virus “may be circulating widely in U.S. swine at this time,” the CDC said, citing U.S. Department of Agriculture surveillance programs.