A report into the porcine epidemic diarrhea virus (PEDv) outbreak that had a significant negative effect on pig industry productivity in parts if the US and Canada last year was most likely spread by contaminated feed containers, concludes a report.
The US Department of Agriculture’s Animal and Plant Health Service (APHIS) carried out a detailed investigation into how the virus arrived in the US and the risk of another disease following the same path.
The study points to Flexible Intermediate Bulk Containers (FIBCs or “tote bags”) as the most likely medium for enabling the virus’ entry in to the US; its rapid and wide spread across the country and introduction onto individual farms. “Several of the farm investigations as well as an early case-control study suggested feed or feed delivery as the source of the outbreak; however, there were no common feed manufacturers, products, or ingredients in the initially infected herds. In addition to meeting the investigation criteria, the contaminated FIBC scenario explains the apparent anomalous association of the epidemic to feed,” states the report.
APHIS speculate that the FIBCs become contaminated in the origin country factors including transport in contaminated trucks, exposure to waters containing animal manures, by birds, by contaminated crops such as soya or by other products and uses. The reuse of the bag once in the US for the transport of bulk feed or ingredients, including recycled food or feed products, could spread the virus through distribution companies, the network of feed mill customers and onto farms. “Once a contaminated FIBC or its contents are delivered to a local mill that manufactures pig rations, the FIBC or its contents would contaminate feed or ingredients destined for delivery to the farm.”
Other virus spread mechanisms considered less likely include accidental or intentional introduction by people, contaminated feed supplements (antibiotics, vitamins, and minerals), spray dried porcine plasma, release from a diagnostic laboratory or research facility, contaminated biologicals or injectable medications, contaminated semen or germplasm, birds, the import of prohibited products or a wildlife reservoir of the virus.
The full report is available via: https://www.aphis.usda.gov/animal_health/animal_dis_spec/swine/downloads/secd_final_report.pdf