As the USDA has worked through some of issues surrounding a federal mandate on porcine epidemic diarrhea (PED) virus and swine delta coronavirus, the agency has set labels and protocols for the different phases of infection. The new labels will assist the pig industry with diagnostic sampling, as well as reporting the viruses.

The goal was to create a uniform language for producers, veterinarians and laboratories classify the viruses. These definitions are designed to help producers understand when and what will be required of them if they experience a PED virus outbreak or reoccurrence. 


The defined stages of disease infections, according to Michigan State University Extension, include:

  • Suspect – Observation of acute contagious (spreading) watery diarrhea on a farm. When the suspect stage is discovered, the action necessary is to contact the herd veterinarian and complete sampling for diagnostic positive.
  • Presumptive positive – There are no clinical signs, but diagnostic test indict positive animals. When the presumptive positive stage is detected, producers and veterinarians should submit diagnostic tests with national premises ID number and other required information to the USDA or a state veterinarian.
  • Confirmed positive – Positive diagnostic tests and observed clinical signs are found, based on colonic PCR samples. When this stage is found, like with the presumptive positive stage, diagnostic tests with national premises ID number and other required information should be sent to the USDA or state veterinarian.  Also, a health management plan should be implemented and completed at the infected site. Finally, required documentation should be provided to the state veterinarian’s office, which will then be documented and forwarded to the USDA.