<P> Swine influenza is an infection caused by any one of several types of swine influenza viruses . Swine influenza virus ( SIV ) or swine - origin influenza virus ( S - OIV ) is any strain of the influenza family of viruses that is endemic in pigs . As of 2009 , the known SIV strains include influenza C and the subtypes of influenza A known as H1N1 , H1N2 , H2N1 , H3N1 , H3N2 , and H2N3 . </P>
which animal is the carrier of the h1n1 virus
pigs