The Animal Health Laboratory (AHL) had diagnosed Swine Delta Coronavirus (SDCV) in samples from six Ontario pig farms as of mid-March, according to the American Association of Swine Veterinarians (AASV). The pathogen was detected as a result of follow up testing on farms with clinical signs of vomiting and diarrhea, but that tested negative for Transmissible Gastroenteritis (TGE) virus and Porcine Epidemic Diarrhea Virus (PEDV). Samples of porcine plasma have also tested positive for SDCV at AHL and Iowa State University. The samples submitted were from the same batch that tested positive for PEDV in February 2014.
These are the first confirmed cases of SDCV in Canada.
SDCV was initially detected in pigs in Hong Kong in 2012. In February 2014, the United States Department of Agriculture along with the Ohio Department of Agriculture issued a press release indicating that SDCV had been detected in swine manure at four farms in Ohio. These farms had pigs exhibiting clinical signs similar to PEDV, and three of the four farms had tested positive for PEDV as well as SDCV.
In light of the U.S. findings, AHL developed a polymerase chain reaction (PCR) test for SDCV, and began testing for the virus in samples from farms that had clinical signs in pigs, yet tested negative for PEDV and TGEV. SDCV testing is currently available free of charge in Ontario for symptomatic herds.
SDCV infection is clinically similar to, but distinct from, PEDV and TGE. It causes diarrhea and vomiting in all age groups and mortality in nursing pigs. Mortality rates appear to be lower than in cases of PEDV. SDCV is not a risk to human health or to other animals, nor is it a food safety risk.
With technological advances, new types of viruses are detected on a regular basis. There are numerous coronaviruses that can cause infections in humans, other mammals and birds, so it is not surprising to find an additional one in swine, according to AASV.
SDCV can be prevented and managed in the same way as PEDV:
- ensuring vigilance and strong biosecurity at the farm level,
- diligent cleaning and disinfection by transporters, renderers, processors and other service providers
- developing herd immunity to reduce clinical signs
Ontario’s pork industry is continuing to work together with increased attention being paid to strict biosecurity measures. Under Ontario’s Animal Health Act, 2009, veterinarians are required to immediately report any findings that identify a serious risk to animal health, such as SDCV.