The Ontario Swine Health Advisory Board (OSHAB) has announced that a new strain of PED was found in a farrow to finish farm enrolled in the Area Regional Control and Elimination (ARC&E) program. The farm was in the final stages of ensuring that the finisher pigs were free of virus when the disease broke clinically. The strain identified was the USA strain OH851, more commonly called U.S. Strain 2. All other cases in Canada were identified as the dominant classical Strain 1.
"The affected farm was one of the first cases of PED in Ontario in February, 2014. The clinical presentation at this farm was unusual with diarrhea in finisher pigs previously exposed to PED virus in the nursery. The variant strain was identified in samples taken from these pigs. This farm is in the final stages of an elimination plan and last week all samples including samples from these finisher pigs tested negative for PED virus. The plan includes elimination of both PED virus strains from this herd.
It is hypothesized that the farm was infected with both viruses in early February from the U.S.- origin contaminated plasma and the second strain remained unapparent and subclinical until now.
Veterinarians are investigating any unusual clinical signs observed at PED-positive sites and together with the laboratories will further analyze virus sequences to ensure this second strain is not more widespread. " (taken from the OSHAB announcement)
Source: Alberta Pork