Where does Swine flu come from?

Classical swine fever has been suggested in connection with human influenza illness during the influenza pandemic in 1918, when the pigs were sick at the same time as the people. The first identification of influenza virus caused disease in pigs have been almost ten years later, in 1930. For the following 60 years of swine influenza H1N1 strains were almost. Then, in 1997 and 2002, three new lines of different subtypes and five different genotypes emerged as causes of influenza in swine in North America. In 1997-1998, H3N2 strains were. These strains, which contain genes from the reassortment of human, swine and avian influenza viruses, has become one of the main causes for the classical swine fever in North America. Arises between H1N1 and H3N2 to H1N2. In 1999, Canada, the H4N6 strain, beyond the species barrier from birds to pigs, but it was in a form farm.The H1N1 swine is one of the progeny, resulting in the influenza pandemic, the 1918th As well as the remains of pigs are descendants of the 1918-virus is also distributed to 20 persons century, to the normal seasonal influenza epidemic. However, direct transmission from pigs to humans is rare, with only 12 cases in the United States since 2005. However, the maintenance of these lines of influenza strains in pigs in the groups were lost as a reservoir of swine influenza virus can survive, emerging later reinfect people as human immunity to this flu strains are waned.Swine are a number of occasions which usually confines itself to the human disease, only rarely, with a wide distribution. Outbreaks of classical swine fever and are causing significant economic losses in the industry, especially on growth disorders and an extension of time to market. For example, the disease has cost the British meat industry? 65 million per year.