The number of confirmed cases and deaths linked to listeriosis have risen as recalls of Maple Leaf Foods products increased, according to public health officials.

There are now 26 confirmed cases of the bacterium, Listeria monocytogenes, up from 21, Dr. Mark Raizenne, director general of the Public Health Agency of Canada's centre for food-borne, environmental and zoonotic infectious diseases, said Monday afternoon at a news conference in Ottawa.

Of those 26, there are 12 confirmed deaths, up from four in Ontario and B.C., Raizenne said. Eleven deaths were in Ontario and one was in B.C., he said. The listeria strain was the underlying or contributing factor in seven of those 12 deaths but the other five, which had the bacterium in their system, are still under investigation, he said.

The number of suspected cases is now 29, down from 30, he said. Those cases are in Alberta, Ontario, Quebec and Saskatchewan.

Public health officials said over the weekend to expect the number of suspected and confirmed cases of listeriosis to increase as the investigation continues because of the bacterium's long incubation period.

The numbers also have changed because provincial public health officials have redefined how they count people affected by the listeria outbreak strain, federal Agriculture Minister Gerry Ritz said.

Lucerne Foods, a Calgary-based distributor of sandwiches, has recalled 27 types of sandwiches sold in Saskatchewan and Alberta. (Larry MacDougal/Canadian Press)

"Our number of confirmed cases will include anyone that had this strain in their body at the time of death, whether it's the actual cause of death or not," he said.

He said this altered the death count and that the change in the case definition was made to "ensure the numbers are as comprehensive as possible."

When government lab tests linked the outbreak strain to some recalled products made by Maple Leaf Foods over the weekend, the company expanded its recall as a precaution to include everything that was made at its plant in Toronto.

Earlier on Monday, the Canadian Food Inspection Agency also said Calgary-based Lucerne Foods was recalling 27 kinds of sandwiches because some contained Maple Leaf Foods deli meats involved in the massive recall.

The sandwiches are sold under the Safeway and TakeAway Café brands at Safeway and Mac's convenience stores in Alberta and Saskatchewan. Lists of the recalled sandwiches and other meat products are available on the CFIA's website.

There have been no reported illnesses associated with the consumption of the sandwiches, the agency said.

More cases of listeriosis expected

On Sunday, federal Health Minister Tony Clement said the number of cases is expected to rise, since people can be infected for a length of time before showing symptoms.

Symptoms of listeriosis — which include high fever, severe headache, neck stiffness and nausea — occur up to 70 days after consuming contaminated food, though the average incubation period is 30 days, the federal food agency said.

Clement's comment came a day after government lab tests showed a conclusive link between the bacteria strain in the listeriosis outbreak to one in some products recalled earlier this month by Maple Leaf Foods.

The test results prompted the company to expand its voluntary recall Saturday to all 220 products made at the Toronto plant as a precaution.

Plant's reopening delayed

The scheduled reopening of the Bartor Road Maple Leaf plant on Monday was postponed to Tuesday due to transportation problems shipping out products so all rooms could be cleaned, company spokeswoman Linda Smith said. But Ritz said the reopening likely won't happen until the end of the week at best and the plant production lines and foods would be tested before any products go to store shelves.

Smith said the problem is a "very localized situation specific" to two of the facility's production lines, which have been dismantled and sanitized under the supervision of microbiologists.

She acknowledged that inspectors failed to detect listeria in this case, but they are constantly swabbing for the bacterium.

"Did we find it? Absolutely not. We did not find that listeria," she said. "Did we let people down? Yes. But we were doing the right things."

Smith said Maple Leaf's practices "meet or exceed regulatory standards by a substantial margin."

"We're inspected regularly by the Canadian Food Inspection Agency. All of our plants are federally registered, the highest level of food safety in Canada and they have full-time inspectors on site," she said.

Rick Holley, a food science professor with the University of Manitoba, said he wasn't surprised to learn of the listeria outbreak since Canada's tracking of food-related illnesses is inadequate.

"I am constantly troubled by the lack of surveillance information on food-borne and water-borne illnesses in Canada," said Holley.

He said the United States tracks down each type of food-borne illness, resulting in safer practices and better detection.

Maple Leaf Foods estimates the recall will directly cost the company at least $20 million, with further losses expected due to lost sales and advertising to rebuild its image.

The recalled meats bear the establishment number of the Toronto facility, 97B, on their packages next to the best before or packed on dates. That establishment number will not appear on the sandwiches.

People most at risk include newborns, the elderly, pregnant women and people with weakened immune systems, public health officials said. The public should wash produce and avoid unpasteurized milk and dairy products, the CFIA advised.

Public health and company officials said the source of the contamination may never be found since listeria is so widespread and commonly found in the environment, such as in soil and in water.