"As of today, 38 cases of listeriosis have been reported and 13 have been confirmed as linked to the outbreak" in Ontario province, including one death, said Ontario associate chief medical officer David Williams.
Seventeen of the Ontario cases are still under investigation, and eight have been ruled not linked to the outbreak, Williams said.
The Public Health Agency of Canada, meanwhile, reported four other confirmed cases: two in westernmost British Columbia, one in Saskatchewan and one in Quebec.
The source of the contamination is still being investigated, officials said.
"A single manufacturer of the foods has been identified as the probable source as positive for the bacterium," Williams said. "However, there's no definitive link."
While health officials continue to search for the source, he said: "Let me strongly reiterate to watch what you eat."
On Tuesday, the Canadian Food Inspection Agency issued a national recall of Maple Leaf sliced corned beef, roast beef, pepperoni, salami, sausages, smoked ham, and turkey believed to be contaminated with the bacteria listeria monocytogenes.
All of the initial cases had involved elderly long-term care or hospitalized patients, but the illness has since spread, officials said.
Maple Leaf has now "identified the listeria in their production line," but is waiting for laboratory confirmation that it is the same strain, Williams said.
Food contaminated with listeria monocytogenes may not look or smell spoiled, but eating it may cause high fever, severe headache, neck stiffness and nausea.
Pregnant women, the elderly and people with weakened immune systems are particularly at risk. Infected pregnant women may experience only a mild, flu-like illness, but infections can lead to premature delivery, or stillbirth.