Human swine flu in pigs
The Editors of Effect Measure are senior public health scientists and practitioners. Paul Revere was a member of the first local Board of Health in the United States (Boston, 1799). The Editors sign their posts "Revere" to recognize the public service of a professional forerunner better known for other things.
...we started seeing pigs infected with human pandemic swine flu, both in the lab and in pig herds. It's likely the pigs got it from us, although which direction things went in isn't completely clear. But originally the virus made the jump from pigs to humans, probably sometime in late 2008 or early 2009, and now it's likely moving back and forth. Finding the human virus in pig herds in Canada, the US, Norway, Argentina and Northern Ireland, the current official line from the ag industry is, "No surprise. Nothing to see. Move right along."
...industrial pork production packs large numbers of animals together in unsanitary and highly stressful conditions, the perfect incubator for a more virulent virus. In this setting there is a selective advantage to produce more numerous and perhaps more severe symptoms because sick animals can transmit the virus easily, even if they sicken and die. So the establishment of this new ecological niche for the virus in animals in contact with humans and consumers is a concern.
At the moment the virus isn't even making the pigs sick, so it is most likely H1N1 pigs are moving into the food chain. If you cook the pork you will kill (more accurately, inactivate) the virus. But the pork on the dinner plate isn't the only consumer or health concern. Infected and uncooked pork and even infected live pigs routinely come in contact with people in the process of husbandry, slaughter, butchering, packaging and food preparation. While it is most likely true you can't get swine flu from eating pork, there are many other possible modes of transmitting infection from infected swine.
Read their complete commentary here: http://scienceblogs.com/effectmeasure/2009/10/human_swine_flu_in_pigs.php