A third province has been affected by an E. coli outbreak, which is believed to be linked to contaminated romaine lettuce.

The Public Health Agency of Canada says it is aware of one E. coli case in New Brunswick, in addition to the three in Ontario and 15 in Quebec that were reported earlier this week. Thirty-two illnesses have also been reported across 11 states in the U.S.

The agency is warning residents of all three provinces not to eat any romaine lettuce until the specific source of the contamination has been identified, though it has stopped short of issuing a recall on romaine lettuce.

In the absence of an official recall, several major retailers have taken to removing potentially contaminated products from their shelves themselves. , , Walmart, Metro and all say they have stopped selling romaine lettuce and salad mixes containing romaine.

Additionally, customers are being told they can return products containing romaine to the point of purchase for a full refund.

The retailers have stopped selling romaine across the country, even though the Public Health Agency of Canada has given no indication that people west of Ontario and in some Atlantic provinces are at risk.

Shoppers outside the affected area appear to be taking the same approach. Several told CTV Winnipeg that they had no interest in consuming romaine lettuce until the source of the outbreak has been identified.

鈥淚t鈥檚 going back to the store where it came from,鈥� Kathy Murdoch said.

鈥淚t comes from America 鈥� so I鈥檓 not going to take a chance.鈥�

University of Manitoba food sciences professor Claudia Narvaez agreed, saying people should not take any chances with their health by gambling on romaine lettuce.

鈥淚t鈥檚 pretty serious bacteria. You don鈥檛 want to take that risk,鈥� she said Tuesday.

The Canadian Food Inspection Agency has said it will recall specific romaine products if the exact source of the contamination is identified, and for now is advising only that 鈥渞etailers and restaurants should take appropriate action.鈥�

With a report from CTV Winnipeg鈥檚 Michelle Gerwing and files from The Canadian Press