Swine Flu, also called Swine influenza, H1N1
flu, hog flu, and pig flu, is an infection by any one
of several types of swine influenza virus.
Swine influenza virus (SIV) 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, H3N1, H3N2, and
Swine influenza virus is common throughout pig populations
worldwide. Transmission of the virus from pigs to humans
is not common and does not always lead to human influenza,
often resulting only in the production of antibodies
in the blood. If transmission does cause human influenza,
it is called zoonotic swine flu.
People with regular exposure to pigs are at increased
risk of swine flu infection. The meat of an infected
animal poses "NO Risk" of infection when properly
During the mid-20th century, identification of influenza
subtypes became possible, allowing accurate diagnosis
of transmission to humans. Since then, only 50 such
transmissions have been confirmed. These strains of
swine flu rarely pass from human to human.