It has caught the industry off guard because before this, the province had only 10 outbreaks over several years.
There were 40 outbreaks by the end of June, and now 11 more in little more than a week, according to Andrew Dickson, general manager of the Manitoba Pork Council.
"It caught us off-guard," Dickson said Monday.
"We had a total of 10 cases in three years, so that's what's throwing us off for a loop ... What happened this year that we've suddenly got 50?"
He said the virus has so far been contained to about a half-hour's drive radius surrounding Steinbach, southeast of Winnipeg, and farmers are doing what they can — including reviewing biosecurity measures, equipment and clothing — to stop it from spreading.