Canada's Public Health Agency is investigating an outbreak of E. coli O157:H7 which may be linked to leafy green vegetables such as lettuce, kale, spinach, arugula or chard.

The organization said that a specific food product has not yet been identified as the source of the infection, but the public health risk is low. To help avoid illness, consumers should always wash fruits and vegetables before eating them, and thoroughly clean kitchen counters and cutting boards.

In the meantime, the investigation into the outbreak is continuing. If products are identified, the Canadian Food Inspection Agency will inform the public and launch an immediate recall.

Twelve cases of E.coli with a matching genetic fingerprint were reported last month in Alberta (9), Saskatchewan (1), Ontario (1) and Newfoundland and Labrador (1).

Most people made ill by E. coli will experience a few days of upset stomach and then make a full recovery, but infections can sometimes be life-threatening. Those most at risk of developing serious complications are pregnant women, people with compromised immune systems, young children and older adults.

Symptoms may include severe stomach cramps, watery or bloody diarrhea, vomiting, nausea, headache and slight fever.

The Public Health Agency of Canada said that it would continue to monitor for and investigate any new cases of E.coli that may be related to this outbreak, in collaboration with federal and provincial/territorial partners.