WASHINGTON (Reuters) - The pandemic H1N1 influenza virus has been found for the first time in a commercial swine herd, the U.S. Agriculture Department said on Monday.

A pig is seen during a campaign by Peru's Agriculture Ministry to promote the consumption of pork in Lima May 5, 2009. REUTERS/Enrique Castro-Mendivil

The sick herd was found in Indiana, the USDA said, noting both the pigs and their caretakers have fully recovered from the virus, commonly called swine flu. USDA said the Indiana facility has continued its routine processing practices because it is safe for swine that recover from influenza viruses to be slaughtered.

A USDA spokesman said it could not release the city, name of the facility or the size of the herd where the pandemic H1N1 virus was found “in order to ensure continued high levels of participation in swine surveillance efforts, and because this is not a food safety or public health risk.”

The human form of the new H1N1 virus, which emerged in March and was declared a pandemic in June, is circulating the globe. Researchers at The Centers for Disease Control estimated last week that as many as 5.7 million people in the United States have been infected so far, with at least 1,300 deaths.

Last week, USDA said six pigs shown at the Minnesota State Fair in September had been confirmed as having had the pandemic H1N1 flu virus. The USDA found the virus in the first U.S. hog on October 19 -- one of the six positives from the fair.

“It’s expected that pigs will get this particular flu strain just like pigs every year get the flu,” said Dave Warner of the National Pork Producers Council, who added he would not be surprised to see more cases of pandemic H1N1 in U.S. hogs.

“It’s just not an issue. It’s not unexpected,” he said.

World health officials have stressed the flu cannot be contracted from eating pork.

But the virus has affected pork trade, most notably to China, which has banned U.S. pork since May because of the outbreak in humans. Chinese officials said last Thursday they plan to lift the ban.

The USDA’s finding appeared to have little impact on hog markets on Monday as analysts had forecast for some time that humans could transmit the flu to hogs.

Hog futures were higher in afternoon electronic trading following USDA’s announcement before drifting back to near unchanged from the pit close. Also, shares of Smithfield Foods Inc, the largest U.S. hog and pork producer, were up on the New York Stock Exchange.

Hog futures have sped higher recently as investment funds have poured money into the market.

“This may stall the rally for a moment, but I don’t think it’s over,” Rich Nelson, analyst at Allendale Inc, said of Monday’s news.

Jim Clarkson, livestock analyst with A&A Trading Inc, added that he doesn’t expect any market reaction until all the facts become available regarding the size of the herd and what is being done to keep it in check.

“I don’t know that anybody is going to react to something like that until it’s confirmed and you know what kind of size it (hog operation) is,” said Clarkson.

The new strain of H1N1 virus, which has genetics from swine, birds and humans, likely circulated undetected in pigs for at least a decade before jumping to humans, according to an expert at the University of Arizona.

Swine flu, common in hogs around the world, causes fever and coughing in pigs, which usually recover from the illness. The virus has been found in several herds in Canada.

USDA said it would post all future suspected and confirmed pandemic H1N1 influenza detections on a spreadsheet at www.usda.gov/H1N1flu.