According to the Public Health Agency of Canada (PHAC), recent cases of Escherichia coli O157:H7 (E. coli) could possibly be linked to leafy green vegetables--specifically arugula, chard, kale, lettuce and spinach. 

PHAC says the agency is currently aware of 12 E. coli illnesses--all reported in March--in the Canadian provinces of Alberta, Labrador, Newfoundland, Ontario and Saskatchewan. However, no specific product has been identified as the cause of the outbreak.

In general, contaminated leafy green vegetables are particularly dangerous because they are eaten raw and are not typically cooked at high temperatures that might destroy bacteria. While PHAC maintains that the risk to the public is rather low, consumers are encouraged to always wash fruits and vegetables before eating them, and to thoroughly clean kitchen countertop surfaces and cutting boards.

The Canadian Food Inspection Agency continues to investigate this matter.