There’s been a great uptick in interest over the past couple of years in the environmental and ethical problems with the ways animals are conventionally raised in modern industrial agriculture settings. That, combined with the rise of swine flu, has naturally led to interest in the issue of whether or not the emergence and spread of the H1N1 virus is linked to pig Concentrated Animal Feeding Operations (CAFOs) in some damning way. Grist is hosting an interesting debate on the subject, with Tom Philpott making the case for links and Merritt Clifton pushing back and saying the evidence really isn’t in.
I’m not an expert, but my understanding of the general issue of animal-to-human flu strain “jumps” is that it is related to agriculture, but not necessarily to the CAFO question. The reason these transmission cases typical involve chickens (“avian flu”) or pigs (“swine flu”) is that these are the animals most commonly raised by man. And chicken and pig viruses are subject to animal-to-human transmission in part because it’s common for people and their animals to be living in extremely close quarters in the developed world. It’s true that strict adherence to humane treatment of free range animals would mitigate that risk. But the locus of the problem is less the state-of-the-art developed world CAFOs than it is developing world agricultural practices.
That’s in general. Of course in general these things also usually happen in Asia, where those practices are widespread. Since this particular flu arose in Mexico, where conditions are different, it’s not unreasonable to think that the circumstances of origin are different.