Though much remains unknown about the spread of ‘Swine Flu,’ a potentially deadly strain of influenza that appears to have migrated from pigs to humans in Mexico and, now, the United States, a growing chorus of critics of industrial agriculture is asking whether confined animal feeding operations (CAFOs) are to blame.

As the Huffington Post’s David Kirby wrote as news of the outbreak first broke:

For years, leading scientists around the world have worried that large-scale, indoor swine “factories” would become breeding grounds for new pathogens that could more easily infect humans and then spread out rapidly in the general population – threatening to become a global pandemic.

We know that hog workers in Europe and North America are far more likely than others to be infected with potentially lethal pathogens such as MRSA (Methicillin-resistant Staphylococcus aureus), drug-resistant E. coli and Salmonella, and of course, swine influenza. Many scientists also believe that people who work inside CAFOs are more at risk of contracting and spreading these and other “zoonotic” diseases than those working in smaller-scale operations, with outdoor pens or pasture and far lower animal density.

But until now, hog workers with swine flu have rarely gone on to infect other people, save for close family members. And that is why this new strain of swine influenza virus is so vexing – and alarming. It seems to spread quite easily through casual human contact.

It bears repeating that the jury is still out on the source of the swine flu outbreak, and Mexico’s hog industry denies responsibility.  It does appear, at this point, that the virus migrated from a pig to a human, but we do not yet know where or precisely how.  Still, Kirby follows up with some additional reporting that seems to suggest that CAFOs had something to do with it.

Depending on how the public health investigation being undertaken by U.S. and Mexican officials turns out, it could have a significant impact on how we regulate agriculture in Iowa.