Are Pig Farms Flu Factories?

American pig farms basically act like "flu factories," says an article in Scientific American. It's another unintended consequence of cheap meat.

The outbreak of bird flu (H5N1) five years ago and last year's swine flu (H1N1) pandemic resulted from viruses jumping from animals into humans, which led to some calls for increased monitoring of birds and pigs on farms.

But Helen Branswell says in an article in this month's Scientific American that pig farms in America basically act like "flu factories." (Branswell's piece is behind a pay-wall, but you can listen to this short, informative podcast.) She says the pork industry doesn't want to share data and results from on-farm pig flu testing over the fear that any reported illness will hurt their bottom line again. After all, the 2009 swine flu pandemic caused pork sales to plummet.

Given these circumstances, it's not difficult to imagine another potentially dangerous pandemic virus originating from pig farms. One official at Centers for Disease Control and Prevention even said that by the time the center receives reports of humans catching a flu virus, those pigs will have been sent off to the slaughterhouse, making the disease nearly impossible to trace.

Perhaps that should be another unintended consequence of cheap meat worth thinking about.

Illustration from "Antigenic and Genetic Characteristics of Swine-Origin 2009 A(H1N1) Influenza Viruses Circulating in Humans," published in Science July 10, 2009.