Swine influenza virus (referred to as SIV) refers to influenza cases that are caused by Orthomyxoviruses endemic to pig populations. SIV strains isolated to date have been classified either as Influenzavirus C or one of the various subtypes of the genus Influenzavirus A. Swine flu infects people every year and is found typically in people who have been in contact with pigs, although there have been cases of person-to-person transmission. Symptoms include fever, disorientation, stiffness of the joints, vomiting, and loss of consciousness ending in death. Swine influenza is known to be caused by influenza A subtypes H1N1, H1N2, H3N1, H3N2, and H2N3