What was suggested as the most likely entry route of PED into the United States?

The most likely entry route of Porcine Epidemic Diarrhea (PED) into the United States is associated with flexible intermediate bulk containers containing pig feed. These containers are widely used for transporting bulk materials, including animal feeds and ingredients, and can carry pathogens if contaminated.

Research indicated that contaminated feed ingredients, particularly those imported from affected regions, played a key role in the spread of PED. The viral particles of PED can survive in feed and feed products, presenting a significant risk for introduction into herds. It is of particular concern that these containers can easily be manufactured and shipped across international borders, making them a feasible vector for such diseases.

Other potential routes, while they might carry risk factors, have not been supported with as much evidence or were less likely compared to the contamination of feed materials. For instance, the idea of a cross-species jump from prairie dogs remains speculative, and feral swine from Mexico, while a potential vector for other diseases, have not been directly tied to PED as a primary mode of introduction. Additionally, the feeding of food waste—while it can be a risk for other pathogens—has less direct evidence linking it specifically to PED. Thus, the contamination of pig feed in flexible intermediate containers stands out as the