TORONTO - Ontario's chief medical officer of health is warning people not to eat a Strubs brand of smoked salmon because it may be contaminated with Listeria.

It's identified as ready to eat smoked salmon, Lot Identifier: 09192011 and distributed in 250 gram vacuum packs, the agency said in a release Thursday.

The processing plant is in Toronto but the extent of the distribution across Ontario is not known. It is sold in supermarkets, grocery stores or delis and people should throw it out or return it to the retailer.

There have been no reported illnesses.

Dr. Arlene King says people at high risk for listeriosis, such as the elderly, pregnant women and those with weak immune systems should not eat the salmon.

Listeria can cause listeriosis, a serious but rare illness. Listeriosis usually manifests as mild flu-like illness and symptoms can include vomiting, nausea, cramps, severe headache, constipation or fever.

More severe illness may result in meningitis and blood infection in newborns and adults.