Lost amid the panic over the growing swine flu epidemic is a key question: How did it start? According to sources in the United States and Mexico, the culprit may be Smithfield Foods, the world’s largest owner of hog farms, which operates hog-raising operations in Perote, Mexico. Perote is located in the state of Vera Cruz, where the outbreak began, and a third of the population had reported symptoms of flu. Smithfield’s operation in Mexico is known as Granjas Carroll, where almost one million hogs are raised each year. The blog Biosurveillance published an account out of Mexico that said residents in Perote believed the flu outbreak was caused by contamination from hog farms in the area.