For now, swine are still welcome at the Minnesota State Fair.

In spite of a new strain of flu that's been jumping from pigs to people, the Minnesota Department of Health gave the go-ahead Tuesday to the 1,000 or so swine heading to the fairgrounds for Thursday's opening day.

"We've [taken] a lot of precautionary measures that should reduce an already low risk," said Richard Danila, the deputy state epidemiologist.

After consulting federal health officials on Tuesday morning, Danila said the department might "tweak" warnings to fairgoers about reducing their risk of exposure. That may include keeping newborn piglets out of reach of visitors at the Miracle of Birth petting barn.

But he was not willing to go as far as Michael Osterholm, a former state epidemiologist, who said this week that swine should be barred from state fairs, including Minnesota's, because of the flu risk.

"I think we're taking measures that are commensurate with the risks," Danila said.

On Monday, Osterholm, an expert in infectious disease at the University of Minnesota, warned that officials were "tempting fate" by allowing the swine exhibits to proceed while the new virus is spreading. He warned that the precautions being taken -- such as urging visitors to wash their hands after visiting swine exhibits -- have not been shown to prevent spread of the flu virus.

In the past few months, some 250 people across the country have been infected by a new strain of flu, H3N2v, that has spread from pigs to humans at state and county agricultural fairs. Minnesota's first case of the new strain was confirmed Monday.

Osterholm said his main concern is that the virus, which has been mild so far, can change and become much more dangerous every time it jumps from one species to another. He noted that this level of pig-to-human transmission "is unprecedented. We've never seen this anywhere before." The fear, he said, is that state fairs could become the breeding ground for a global public health threat.

Danila, however, said that he consulted officials at the U.S. Centers for Disease Control and Prevention and that "they basically are in 100 percent agreement with us."

He said the Health Department plans to post new signs at swine exhibits warning visitors not to touch the animals or eat in the swine barns. Children younger than 5, as well as other vulnerable groups such as pregnant women, the elderly and chronically ill, should avoid swine entirely, department officials warned.

The Miracle of Birth barn, where adults and children can pet newborn animals, might take additional precautions, Danila said. They are considering testing the pregnant sows for the flu virus, as well as urging the exhibitors to keep piglets out of reach of visitors this year.

Danila noted that the risk of infection has been relatively low. An estimated 80 million people have visited state and county fairs this season, he said, yet there have been only about 250 human cases of the new flu strain.

"The vast majority of those cases were either in swine exhibitors or people who had prolonged swine contact,'' he said. "There are a few cases of people walking through the barns [and getting sick], but not many."

Maura Lerner • 612-673-7384