Swine influenza (also called Pig influenza, swine f lu, hog flu and pig flu) is an infection by any one of several types of swine influenza virus. Swin e influenza virus (SIV) or S-OIV (swine-origin influenza virus) is any strain of the influenza fam ily of viruses that is endemic in pigs. As of 2009, the known SIV strains include influenza C and the s ubtypes of influenza A known as H1N1, H1N2, H3N1, H3N2, and H2N3. Swine influenza virus i s common throughout pig populations worldwide. Transmission of the virus from pigs to h umans is not common and does not always lead to human influenza, often resulting only in th e production of antibodies in the blood. If transmission does cause human influenza, it is call ed zoonotic swine flu. People with regular exposure to pigs are at increased risk of swine flu infection. The meat of infected animal posses no risk of infection when properly cooked.