Swine-Origin 2009 A(H1N1) Influenza Viruses

Hmmm, it did origin from pig and successfully spread among human.

Current information on Tracking the progress of H1N1 swine flu

Antigenic and Genetic Characteristics of Swine-Origin 2009 A(H1N1) Influenza Viruses Circulating in Humans, Published Online May 22, 2009, Science DOI: 10.1126/science.1176225.
Since its identification in April 2009 an A(H1N1) virus containing a unique combination of gene segments from both North American and Eurasian swine lineages has continued to circulate in humans. The lack of similarity between the 2009 A(H1N1) virus and its nearest relatives indicates that its gene segments have been circulating undetected for an extended period. Its low genetic diversity suggests the introduction into humans was a single event or multiple events of similar viruses. Molecular markers predictive of adaptation to humans are not currently present in 2009 A(H1N1) viruses, suggesting previously unrecognized molecular determinants could be responsible for the transmission among humans. Antigenically the viruses are homogeneous and similar to North American swine A(H1N1) viruses but distinct from seasonal human A(H1N1).

The origin of swine flu: Putting the pieces together
May 28th 2009 | NEW YORK, The Economist

YOU are now officially permitted to blame the pigs. .....

A new study, however, suggests pigs really were to blame. Several dozen researchers, led by Rebecca Garten of America’s Centres for Disease Control and Prevention (CDC), sequenced full or partial genomes of 76 samples of the new virus, which has afflicted almost 13,000 people around the world so far. In a paper published in Science, they confirm that the closest genetic relatives of the new virus are swine-flu strains from both North America and Eurasia. The virus is made of eight gene segments of known provenance but which have not previously been seen in this combination. The genetic material in them is indeed a hotchpotch derived from avian, human and swine sources, but all eight segments come most recently from pigs.