By Missoula Current

Wal-Mart this week issued a recall of frozen pizzas available in Montana and 10 other states due to concerns over listeria contamination, the U.S. Department of Agriculture said.

Nearly 7,000 pizzas sold under the Marketside brand through Wal-Mart were affected by the recall.

According to Reuters, RBR Meat Company recalled about 21,000 pounds of Marketside Extra Large Supreme Pizza that were sold in Montana, Washington, Oregon, Colorado, California, Nevada, Idaho, Utah, Wyoming, Alaska and Hawaii.

The product carries the code 20547.

Wal-Mart and the USDA said they were unaware of any illnesses linked to the pizzas, though the retailer started removing the products from its shelves and inventory after it received notice of the recall from Rose & Shore, a food company affiliated with RBR.

Listeriosis is a dangerous illness caused by eating food contaminated with listeria bacterium. The infection is most likely to sicken pregnant women and babies, adults older than 65, and people with weakened immune systems.

The USDA's Food Safety and Inspection Service said people should not eat the pizzas. It said RBR discovered the possible listeria contamination during routine sampling.