Heads of romaine lettuce.Justin Sullivan/Getty Images
The Canadian Food Inspection Agency is warning the public not to consume the True Leaf Farms brand bagged, chopped romaine because it may be contaminated with Listeria monocytogenes.
The affected product was distributed in Calgary and Edmonton and sold in six-by-two-pound bags with a best-before date Sept. 29, 2011.
There have been no reported illnesses associated with the product.
Food contaminated with Listeria monocytogenes may not look or smell spoiled, but can cause high fever, severe headache, neck stiffness and nausea.
Pregnant women, the elderly and people with weakened immune systems are particularly at risk.
The importer, Northern Lights Produce Network Ltd. of Edmonton is voluntarily recalling the affected product.