Veterinary epidemiologist says all the cases, involving 78 premises, were confined to southeastern Manitoba
Every day, volunteers in some of Alberta’s hog barns and handling facilities collect manure samples. They’ve been doing it for more than a year as part of surveillance for porcine epidemic diarrhea virus.
More than 200 samples are tested each month from barns, processing plants, transport trucks and truck washes.
PED, an illness usually fatal to young piglets, was first found in Canada in January 2014 in Ontario, where it spread to 104 premises and continues to be a problem. Five additional premise infections have been reported this year in Ontario, although the last one was in June.
So far, the virus has not infected any pigs or premises in Alberta, Saskatchewan or British Columbia.
Dr. Julia Keenliside, a veterinary epidemiologist with Alberta Agriculture, said surveillance and producer attention to biosecurity have been key to keeping the three western provinces virus-free.
“We have not had any positive PED confirmed in a pig or on a farm in Alberta, Saskatchewan or British Columbia since the start of the outbreak,” she said during an Alberta Pork event earlier this month.
“And we also have not had porcine delta corona virus confirmed in a pig or on a premise since the start of the outbreak in Saskatchewan, Alberta or B.C. I think that is a fantastic piece of news.”
Manitoba has not been so fortunate. An outbreak in April resulted in 78 premises getting infected, comprising 25 sow operations, 16 nurseries and 37 finishers. All were confined to southeastern Manitoba, which Keenliside and Manitoba chief veterinary officer Dr. Glen Duizer said was a major accomplishment given the ease with which the virus can spread.
Keenliside warned against complacency in the West, noting Alberta had one positive test for delta coronavirus, a similar enteric illness, from an assembly yard this year. Saskatchewan has also had two positive tests for that virus and for PED.
That means the virus has been there though not necessarily alive, said Keenliside. The test method called PCR (polymerase chain reaction) detects the viral protein but doesn’t indicate whether the virus is alive and therefore infectious.
The protein itself it hard to get rid of, said Keenliside. Tests show it can persist on trucks even after two washes.
“We continue our surveillance program in Saskatchewan and Alberta. B.C. has discontinued theirs because of funding and the fact they have very few swine farms there. They’re watching our surveillance program and it’s reported to me that they will start testing if we start having problems in Alberta.”
Keenliside said surveillance allows provinces to confirm their negative status for PED and delta corona, and serves as an early warning system if a live virus does arrive.
PED came to Canada from the United States, where it was first identified as a major issue in May 2013. Since then, millions of piglets have died from the virus in the U.S. and it is generally considered endemic, meaning that it commonly occurs and is unlikely to ever be eradicated.
“I think there are systems and areas within the U.S. that are attempting to eradicate the disease or at least bring it to the level of control where its occurrence would be very, very infrequent,” said Duizer.
The U.S. refers to the group of viruses as Swine Enteric Corona Virus Disease in its reporting.
Figures indicate it continues to spread, with 41 new positive cases reported in the week of Sept. 2, the most recent period for which statistics are available.
“Even though the U.S. has progressed tremendously in understanding the epidemiology of the disease and controlling the disease and utilizing vaccination, it still does remain an active disease in the U.S. and it still does remain a source of virus for us, and we have to think about that with our transport links to the U.S.,” said Keenliside.