Swine flu, also referred as swine influenza, hog flu, and pig flu, which is an infection caused by any of the numerous types of influenza viruses, has spread to many parts of the world including India. The swine-origin influenza (SOIV) or swine influenza virus is reported to be any strain of the viruses’ influenza family endemic in pigs. By 2009, SIV strains known include H1N1, H1N2, H2N3, H2N1, H3N1, and H3N2.
Swine influenza virus is found in pigs all over the world, but transmission of these viruses to humans is not usual or common, and does not necessarily cause human flu. Many times, it leads to the production of antibodies. In case, the transmission does take place, it is referred as zoonotic swine flu. Those in constant touch with pigs carry greater risk of swine flu infection.
Reports of swine flu cases in India have attracted the world attention where more than 25000 people have tested positive for swine flu virus, and around 1370 deaths have been reported by March 2015. Swine flu had first been recognized as a disease during the 1918 flu pandemic. At that moment, pigs fell ill simultaneously with humans. The influenza virus was first detected to be the cause of swine flu by 1928-30. For the next 60 years swine flu strains had only been H1N1. After that, other strains of three different subtypes and five genotypes were detected.The H1N1 type of swine flu has been the descendents of the same strain that caused 1918 flu pandemic. Swine flu has been in the news several times as Zoonosis in human beings, rarely distributed far and wide.