US officials suggest swine flu may have originated in Asian pigs.
The New York Times reports, “Contrary to the popular assumption that the new swine flu pandemic arose on factory farms in Mexico, federal agriculture officials now believe that it most likely emerged in pigs in Asia, but then traveled to North America in a human.” However, “they emphasized that there was no way to prove their theory and only sketchy data underpinning it.” Officials note the lack of evidence that the virus “has ever circulated in North American pigs, while there is tantalizing evidence that a closely related ’sister virus’ has circulated in Asia.” Dr. Amy L. Vincent, a swine flu specialist at the Department of Agriculture, said, “The most likely scenario is that it came over in the mammalian species that moves most freely around the world,” people.
