OTTAWA - The Canadian Food Inspection Agency says Gills brand Fresh Diced Red Onions are being recalled because of possible Listeria contamination.

The affected product was sold in 198 gram packages with a best before date of May 17, 2012 (UPC 6 43550 00045 0, and lot code 51RDA1A2119).

The onions were sold in Ontario and possibly elsewhere in Canada, but so far there have been no reports linking them to any illnesses.

Food contaminated with the Listeria monocytogenes bacteria can cause listeriosis, a foodborne illness.

Listeriosis can cause high fever, severe headache, neck stiffness and nausea.

Pregnant women, the elderly and people with weakened immune systems are particularly at risk.