Listeriosis has killed one person in Ontario and made at least 13 others sick, says the province's chief medical officer of health.

Appearing at a news conference on Wednesday, Dr. David Williams said 17 additional people are being tested for a connection to the outbreak.

At least 17 health units throughout the province have seen possible cases, says Williams.

There are reports of four other deaths, but Williams did not confirm the link, saying testing is ongoing.

Meanwhile, Maple Leaf Foods has temporarily closed its North York plant after some products tested positive for the listeria bacteria. Grocery stores across the country began pulling 23 Maple Leaf meat products from store shelves yesterday after the company issued a precautionary recall.

"By tomorrow, 100 per cent of the retail product will be back in our control," says a Maple Leaf spokesperson.

It is not yet confirmed if the strain of listeriosis in the outbreak is the same as the strain found in maple leaf plant, says Williams.

The brands affected in the recall include Schneider, Sure Slice and Burns -- all with establishment number 97-B printed on the labels.

An elderly woman in Hamilton died as a result of complications from the strain of listeriosis linked to the outbreak. Ontario's other confirmed cases are primarily nursing homes residents.

Long term care facilities are being encouraged to ensure residents were not consuming packaged meats, Patterson says.

"I strongly advise members of the public... not to eat any unidentifiable ready-to-eat meat," he says.

Listeriosis is a rare but potentially serious food-borne illness. Its symptoms include high fever, severe headache, neck stiffness and nausea. Pregnant women, the elderly and people with weakened immune systems are particularly at risk.

The incubation period for the infection is from three to 70 days, with an average incubation period of three weeks.

The Canadian Food Inspection Agency says it first became aware of a potential problem with Maple Leaf Foods on August 8, but it took some time to confirm whether a recall was necessary.

The complete list of affected products, including individual product codes and best-before dates, is as follows:

26365, Sliced Cooked Turkey Breast, 470 grams, Sept. 30;
02106, Schneiders Bavarian Smokies, 1 kilogram, Oct. 28;
02126, Schneiders Cheddar Smokies, 1 kilogram, Oct. 28;
21333, Sure Slice Roast Beef, 1 kilogram, Sept. 30;
21388, Sure Slice Combo Pack, 1 kilogram, Sept. 30;
60243, Deli Gourmet Roast Beef slices, 1 kilogram, Sept. 30;
02356, Seasoned Cooked Roast Beef, 500 grams, Oct. 7;
42706, Roast Beef, Seasoned and Cooked, 500 grams, Oct. 7;
21334, Sure Slice Turkey Breast Roast, 1 kilogram, Oct. 14;
21444, Sure Slice Corned Beef, 1 kilogram, Oct. 14;
44938, Montreal Style Corned Beef, 500 grams, Oct. 14;
21440, Sure Slice Black Forest Style Ham, 1 kilogram, Oct. 21;
21447, Sure Slice Salami, 1 kilogram, Oct. 21;
21331, Sliced Smoked Ham, 1 kilogram, Oct, 21;
48019, Deli Shaved Corned Beef, 200 grams, Oct 21;
48020, Schneiders Deli Shaved Smoked Meat, 200 grams, Oct 21;
48016, Deli Shaved Smoked Ham, 200 grams, Oct 21;
48018, Deli Shaved Smoked Turkey Breast,150 grams, Oct 21;
48017, Deli Shaved Fully Cooked Smoked Honey Ham, 200 grams, Oct 21;
21360, Bites Pepperoni, 500 grams, Jan 1, 2009;
99158, Turkey Breast Roast, 1 kilogram, Sept 30;
71330, Roast Beef Cooked, Seasoned, Sept 30;
71331, Corned Beef, Smoked Meat, Sept 30;

The products in the recall have best before dates ranging from September 30 to January 1, 2009.

For public inquires on lysteriosis call the Service Ontario, INFOline at 1-866-532-3161

Contaminated meat may not look or smell spoiled. For more information call Maple Leaf Consumer Foods at 1-800-568-5801.

These products have not been directly linked to human illness but Maple Leaf Consumer Foods has initiated a voluntary recall of the meats.