When swine flu appeared, the pork producers were keen to say there was no connection or relationship between pigs and swine flu (even though the virus’s genetic segments were all of swine origin). They didn’t want anyone to call it swine flu, giving rise to the celebrated naming controversy. But then 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.”
Health experts said the three pigs with the H1N1 virus did not show any symptoms of illness. It?s unknown what happened to those pigs. Health experts say even if they were sent to be slaughtered, it should not cause any concern for humans. People cannot contract H1N1 from eating pork.
The pork industry is being advised to monitor their herds for signs of illness. Ag experts said swine that contract H1N1 usually recover. State health leaders say there is no public health threat as a result of the latest findings. (Judy Ambroz, Fox Philly)
I’m not sure if Minnesota state public health leaders were being coy when they said there was no public health risk “as a result of the latest findings,” but there is most certainly a public health issue from pigs becoming a reservoir for this human virus. The US Secretary of Agriculture, Tom Vilsack, and the National Pork Producers Council take pains to stress you can’t get swine flu from eating pork — assuming no one eats raw or rare pork. But that doesn’t mean there still aren’t public health concerns.
The first is that 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.
I understand why the pork producers are nervous. One report suggests a farmer or big agribusiness company has lost $15 to $30 on every pig sold since the outbreak started, and if herds become widely infected that could get worse. If the virus becomes more virulent in pigs, even if it is just in pigs, producers could lose the whole cost of the animal, since animals that are obviously sick are not supposed to be slaughtered (although we know they sometimes are).
I agree with the pork producers and the Secretary of Agriculture and almost everyone else who knows about this that the discovery of more pig herds infected with this virus is “no surprise.” I don’t agree that makes it no big deal from the public health point of view. Whether it is or isn’t we’ll have to see. Yet while the pork industry is officially on record favoring increased testing and surveillance of the swine population, it is not really to their advantage. They’d rather not know.
Widespread and endemic infection of the pig herds everywhere with this virus would also be “no surprise.” Given the biology and the circumstances, the big surprise would be if it didn’t happen.