Swine flu, also known as 2009 H1N1 type A influenza, is a human disease. People get the disease from other people, not from pigs. The disease originally was nicknamed swine flu because the virus that causes the disease originally jumped to humans from the live pigs in which it evolved. The virus is a "reassortant" -- a mix of genes from swine, bird, and human flu viruses. Scientists are still arguing about what the virus should be called, but most people know it as the H1N1 swine flu virus. The...