Why the Smithfield-H1N1 question matters
some background science
The H1N1 swine influenza virus is a subtype of Influenza-A virus. Influenza-A viruses infect several species of mammals, including humans, pigs, and birds. Pigs in particular are capable of contracting Influenza-A viruses that are normally associated only with birds, only with humans, and only with swine. When Influenza-A viruses commingle within a herd of pigs, they can share genetic information and mutate into a new strain that can be passed from human to human.
This appears to be what has happened with the latest H1N1 outbreak. It contains genetic material from bird, swine, and human influenza viruses and is capable of passing from human to human.
One of the ways Influenza-A viruses can spread is through manure. Given that H1N1 is an Influenza-A subtype it is entirely possible, if not likely, that flies could carry virus-containing manure particles from Granjas-Carroll CAFO lagoons to people. These need not be injected by the flies directly into humans, such as with West Nile Vir