Watch: deadly foreign pig virus swept across the US, killing millions of piglets

Nobody knew how PED spread among farms, but swine feed became a suspect. (file: Amy Mayer/Harvest Public Media)
Nobody knew how PED spread among farms, but swine feed became a suspect. (file: Amy Mayer/Harvest Public Media)

One of the ways researchers study and try to contain outbreaks is by tracing the virus’ path. But that was especially confusing with the Porcine Epidemic Diarrhea virus, or PED.

The Veterinary Diagnostic Lab at Iowa State University first identified PED in the U.S. in May 2013. Then, they went back to samples from hog farms they had in storage and were able to track the virus back to an Ohio farm in April 2013.

From there, it spread quickly. First state diagnostic labs and then the U.S. Department of Agriculture jumped in on the tracking, watching as it hopscotched among unconnected farms, eventually leaping to Hawaii and Puerto Rico.

In about two and a half years, the virus has infected 35 states and taken the lives of about six million piglets. It poses no threat to human health or food safety, though if infections swell in the winter months to come, consumers could be paying a premium for barbecue and bacon next summer, much as they did in 2014.