More than 50 people in the province have signed up to take part in a class-action suit against Maple Leaf Foods, Canada's largest food processing company. Tainted meat from the firm's Ontario plant has been sourced as the root of the contamination. The products were purchased in stores or used in hospitals to feed patients.

In a video posted on YouTube, Michael McCain, the president of Maple Leaf Foods apologised for the outbreak. 'This week our best efforts failed and we are deeply sorry,' he said. 'This is the toughest situation we've faced in 100 years.'

In a press conference, Mr McCain said it was unlikely that the root cause of the contamination would be determined because listeria is so widespread in the environment.

The bacterium is common in food and in nature but can cause a rare form of food poisoning called listeriosis especially among pregnant women, the elderly or individuals with a weakened immune system.

Perry Kendall, the province's chief health officer, says the one suspected fatality in British Columbia was a 64-year-old man with a history of a chronic illness.

Dr Kendall says most food poisoning cases are isolated incidents and minor enough that people recover after a day or two of discomfort. Listeriosis is neither new nor unknown; in the US, there are about 0.25 cases per 100,000 people.

What has troubled British Columbians in particular, suspects Dr Kendall, is the popularity of the prepared meat products and sandwiches in daily life.

'We live in a world of fast food,' Dr Kendall says. 'What could be easier than slapping a few slices of salami or roast beef between pieces of bread for a sandwich?'

Food, nutrition and health professor Christine Scaman at the University of British Columbia in Vancouver says the outbreak has given consumers less confidence in the food industry. 'Consumers rely on the government and the food industry to make sure that the food they buy is safe and they will feel let down,' she says.

A study conducted last year by two Canadian professors ranked Canada's food safety systems as among the most thorough and effective worldwide.

Canadian consumers are used to cheap food and until a recent scare of tainted pet food from China, few people thought about where their groceries were coming from, says Vancouver food consultant Rebecca Robertson. 'This has jolted people. What people are surprised at is ... how many products were produced in one plant. That's making people wonder how concentrated is our food supply in Canada.'

Tomorrow: New York