RED DEER — No one is sure how the porcine epidemic diarrhea virus moved 3,000 kilometres from the nearest known case to arrive in Alberta last January.
“Something transported it in the dead of winter either from Manitoba, Iowa or North Dakota, Washington or Montana,” said swine veterinarian Julia Keenliside of Alberta Agriculture.
“I don’t know how PED got into Alberta. I don’t know how it moved between the farms,” she said.
Sampling of possible sites of infection continues and genetic sequencing results are expected soon to show what linkages might be present.
The cases showed up at Drumheller and the rest were in the Taber area.
Three of four Alberta farms have been declared presumptive negative by the chief provincial veterinarian. All the pigs that were originally infected are gone.
Two rounds of whole barn sampling were negative, all previously infected market hogs have left the premises. Pigs and barns are negative. The lagoon or pits have not tested negative but investigators do not know if the virus is alive.
One farm is still being monitored, Keenliside said.
When the first case was found an emergency response plan between Alberta Pork and the province immediately went into effect, she told the Red Deer swine technology workshop held Oct. 23.
“It is frightening and traumatizing to have so many pigs die. It is an emotionally charged situation,” she said.
“Communication is your number one challenge with a fast-moving disease like this.”
The first goal is to stop it from spreading further. Traceability is a big part of the investigation as they look for transport links between farms, feed mills, assembly yards and abattoirs.
Buffer zones of five, 10 and 20 km were set up around infected farms. All farms within those zones were notified.
Pigs shed the virus four to six weeks intensively after infection so it was important to make sure all were infected at the same time to build immunity. A protocol to move market pigs to slaughter plants was also set up after the greatest risk was past.
Investigators attempted to pinpoint the source but no links were found. Feed, porcine plasma, transport and manure were checked.
Manure equipment that came from Manitoba was tested.
Alberta Pork and the province have been sampling voluntarily for five years at abattoirs, trucks, truck washes and assembly yards, and that testing was doubled after the first case. They tested 2,000 samples in 2019 but found no positive results.
All the farms had good biosecurity but after this incident, stricter measures are needed, Keenliside said.
“Every time you step in that barn, those boots are changed before you come back in. No exceptions,” she said.
PED is an infectious viral disease that kills baby pigs with rates that can reach as high as 100 percent. It appeared in 2013 in the United States and came to Canada in 2014.
Ontario has had 126 total confirmed cases since 2014 and nine cases in 2019.
Quebec has not had a case in several years but two cases appeared in 2019.
Five cases of porcine delta coronavirus were also found for the first time in Ontario and Quebec.
Manitoba has struggled with the disease. There have been 185 cases since 2014 and this year, 78 were confirmed. Manure spreading may be a risk factor. This year’s cases were clustered in May and June, which is also manure spreading time.