What started in early June could claim many more lives by the time listeria's 90 day incubation period has passed. Here's a chornology of events so far.

June 2: Earliest date from which meat prepared at Maple Leaf Foods plant in north Toronto later begins to fall under suspicion of Listeria contamination.

Mid-July: Two people living at the same Toronto nursing home die and are diagnosed with a similar bacterial infection. Ontario health officials begin actively investigating cases of people falling ill.

Aug. 5: Samples taken from Toronto nursing home test positive for listeriosis.

Aug. 6: Canadian Food Inspection Agency notified of the results of Toronto sample testing; returns to nursing home to collect additional samples of meats and cheese.

Aug. 13: Maple Leaf notifies distributors they are under investigation; remaining inventory of Sure Slice roast beef, corned beef and Black Forest ham is put on hold.

Aug. 14: CFIA officials consult with public health officials in Toronto, who in turn tell hospitals and long-term care facilities to stop serving certain meat products and begin collecting additional samples.

Aug. 16: CFIA officials meet with Health Canada and recommend a recall.

Aug. 17: Two specific ready-to-eat products produced at Toronto plant -- Sure Slice roast beef and corned beef -- are recalled.

Aug. 19: Tests on recalled products come back positive; Maple Leaf prepares to expand recall.

Aug. 20: Federal officials confirm one death, 16 other cases linked to listeriosis outbreak. Products from two more Maple Leaf production lines are recalled, bringing total to 23. Toronto plant at the heart of the recall is shut down; Maple Leaf projects cost of recall at about $2 million.

Aug. 22: Officials confirm listeriosis associated with the outbreak caused the deaths of two elderly women in Ontario, bringing official death toll to three. Health officials in B.C. report death linked conclusively to outbreak strain of listeriosis, but death is later reclassified as "under investigation." Royal Touch Foods recalls Shopsy's Reuben sandwich, which contains recalled meat.

Aug. 23: Officials confirm link between outbreak and Maple Leaf products produced in Toronto. Maple Leaf chief executive Michael McCain issues abject apology, describes crisis as "the toughest situation we've faced in the 100 years of this company's history."

Aug. 24: As a precaution, Maple Leaf expands the recall to include all 220 products produced at the plant at an estimated cost of about $20 million. Television commercial featuring McCain's apology begins to air.

Aug. 25: Public Health Authority of Canada officials say six deaths in Ontario conclusively caused by outbreak strain of listeriosis, with six others -- five in Ontario, one in B.C. -- under investigation. Lucerne Foods announces recall of some Mac's and Safeway sandwiches across Western Canada, after some sandwich meat was named in Maple Leaf's latest recall.

Aug. 26: Prime Minister Stephen Harper speaks on the outbreak for the first time, defending Conservative government's handling of the file. Atlantic Prepared Foods Ltd. and Metro Ontario Inc. recall several sandwich products sold in Maritimes and Ontario.

Public Health Authority of Canada officials say numbers of deaths under investigation up to nine from previous six, with 29 confirmed cases nationwide.

Aug. 27: Frances Clark, 89, of Madoc, Ont., becomes first victim of Listeria outbreak identified. Clark died on Aug. 25 in hospital.

Public Health Authority of Canada officials reduce the number of deaths conclusively caused by the outbreak strain of listeriosis to five from six.

The Canadian Food Inspection Agency and Costco Wholesale Canada Ltd. recall two products that contain a ready-to-eat deli meat product previously recalled by Maple Leaf.

The CFIA recalls Cooked Ham and Salami sandwiches sold in Sobeys, Foodland and IGA stores in Ontario because they may contain a ready-to-eat deli meat product previously recalled by Maple Leaf.

Aug. 28: Public Health Authority of Canada officials raise number of deaths conclusively caused by the outbreak strain of listeriosis to eight from five. Twenty-nine cases have been conclusively linked to the outbreak, and an additional 36 suspected cases remain under investigation.

The CFIA recalls Deli Lunch Box Wraps on white or whole wheat sold in Sobeys, Foodland and IGA stores in Ontario because they may contain a ready-to-eat deli meat product previously recalled by Maple Leaf.

The CFIA and White House Meats Inc. of Toronto recalled oven roasted turkey breast sold at two Toronto locations that had been recalled by Maple Leaf.

Elderly woman, who may have died from listeriosis, is laid to rest in Madoc, Ont.

Source: The Canadian Press