This is new as I understand it. It is a combination of four strains of flu, two swine (Eurasian and North American) , one avian and one human.
Here’s an article form Forbes (cannot post directly)
[Schuchat said Thursday that the virus in the United States is influenza A N1H1 mixed with swine influenza viruses. The virus contains genetic pieces from four different flu viruses — North American swine influenza, North American avian influenza, human influenza viruses and swine influenza viruses found in Asia and Europe, she said.
“That particular genetic combination of swine influenza viruses has not been recognized before in the U.S. or elsewhere,” Schuchat said.]