CHICAGO: Pigs in the state of Minnesota may have become infected with swine flu, officials said on Friday, citing preliminary tests taken at a state fair.
If the initial results are confirmed it would be the first case of the pandemic virus detected in US hogs.
"We currently are testing the Minnesota samples to determine if this is 2009 pandemic H1N1 influenza," Agriculture Secretary Tom Vilsack said in a statement.
"I want to remind people that they cannot get this flu from eating pork or pork products."
The pigs sampled at the fair showed no sign of illness and were apparently healthy, the agriculture department said.
However an outbreak of swine flu occurred in a group of children housed in a dormitory at the fair around the same time the tests were conducted from August 26 through September 1.
"Information available at this time would suggest the children were not sickened by contact with the fair pigs," the agriculture department said.
Final test results are expected in a few days.
At least 4,735 people have died from swine flu infections since the A(H1N1) virus was uncovered in April, the World Health Organisation said on Friday.
This is an increase of 210 fatal cases from a week ago when 4,525 deaths were recorded, the UN health agency said in its weekly update of the pandemic.