A large number of salad products sold at retailers such as Walmart, Albertsons, ALDI, BJ’s, Giant Eagle and Safeway stores have been recalled by Fresh Express because they have the potential to be contaminated with listeria.

The affected salad products were produced at Fresh Express’ facility in Streamwood, Illinois, and were discovered during random testing by the Michigan Department of Agriculture of a 9-ounce package of Fresh Express Sweet Hearts salad mix with a use-by date of Dec. 8 at the plant.

The Centers for Disease Control and Prevention has received 10 reports of listeria illnesses detected in random samples from 2016 to the present, according to the recall announcement.

Following the contamination discovery, Fresh Express immediately halted all production at the facility and began a sanitation review. All retailers that received the recalled items were instructed to remove them from store shelves, and all further shipments were stopped.

The recalled salad items were distributed throughout retailers and distributors in the states of Connecticut, Iowa, Illinois, Indiana, Kentucky, Massachusetts, Maryland, Maine, Michigan, Minnesota, Missouri, North Dakota, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island and Wisconsin, as well as in the Canadian provinces of Ontario and Manitoba.

The recall includes all use-by dates of fresh salad items with product codes Z324 through Z350, which are located on the front of the packages below the use-by date.

A full list of items recalled can be viewed here. No other Fresh Express products are affected by the recall, the company said.

Consumers who have these recalled products in their refrigerators are urged not to consume them and to discard them.

To obtain a refund, call the Fresh Express Consumer Response Center at 1-800-242-5472 from 8 a.m. to 7 p.m. ET. Refunds can also be issued at the place of purchase, Fresh Express said.

Listeria can cause serious, and in some instances, fatal infections in young children, frail and elderly adults and those with weakened immune systems. Symptoms can include high fever, severe headache, stiffness, nausea, abdominal pain and diarrhea.

Listeria infection can also cause miscarriages and stillbirths in pregnant women.

Consumers who have symptoms of listeria infections should consult their healthcare provider for treatment.

Salad Kits E
Fresh Express Sunflower Crisp Chopped Salad Kits may be the cause of an E. coli outbreak in the U.S. and Canada. Pre-Packaged salad sits on the shelf at a Bell Market grocery store June 19, 2003 in San Francisco, California. Packaged salad which was near non-existent a decade ago has become the second fastest selling item on grocery shelves behind bottle water, overall the retail market for bagged salad is $2 billion annually. Getty Images/Justin Sullivan