Winnipeg, Manitoba, Aug 21 - Canadian health officials searched for more clues on Thursday into the source and extent of a food poisoning outbreak that has made more than a dozen people sick and caused one death.
Most of the confirmed cases are in the province of Ontario, where the associate chief medical officer told people to throw out any processed sandwich meats that they were unsure about.
"I advise you not to eat any unidentifiable ready-to-eat meat," David Williams said at a news conference.
Williams said he expects to see more cases of listeriosis, a foodborne illness that is a particular risk for pregnant women, the elderly, infants, and people with weak immune systems.
Health officials are looking to see whether other deaths are linked to the outbreak, Williams said. In total, there are 38 cases of listeriosis in the province, but not all may be linked to the outbreak, he said.
"It's very much like very intensive detective work," he said.
Williams said the "probable source" of the outbreak is deli meat from a Toronto plant owned by Maple Leaf Foods Inc , which issued a recall of more than 20 types of deli-style products.
The company and health officials found listeria monocytogenes in two products made by the company, although genetic testing has not yet determined whether it is the same strain that caused the outbreak, Williams said.
Maple Leaf pulled other products made since June on the same production lines as the affected products and temporarily closed the plant as a precaution, it said.
The company's shares have dropped 4 percent in the past two sessions on the Toronto Stock Exchange to C$10.27.
Most of the meat products were sold to restaurants, hospitals, nursing homes and deli counters in grocery stores, and led to McDonald's Canada pulling a turkey sandwich from its menus.
Canada's agriculture minister said Maple Leaf and government officials have taken apart the plant's equipment for a "forensic inspection".
"I think that we will get to the bottom of this," Gerry Ritz said.
But he warned that the investigation was complex, noting some of the contaminated meat samples were found in sandwiches, and that the organism could have come from counters where the deli meats were served.
"You have bread, butter, mayonnaise, lettuce, cheese, and the meat that's in question ... so they're still trying to analyze what component of that may have been the problem," Ritz told reporters.
($1=$1.04 Canadian)