STANWOOD — A national recall of frozen spinach packaged at Twin City Foods here now involves a brand sold in Washington — Wild Harvest.

The recall, announced by the federal Food and Drug Administration, said Wild Harvest and three other brands of frozen spinach could be contaminated with listeria monocytogenes. The food-borne bacterium can cause serious and sometimes fatal infections in young children, the elderly and people with weakened immune systems. Symptoms include high fever, severe headache, nausea and diarrhea.

There have been no reports of anyone in Washington becoming ill from eating the spinach, according to Donn Moyer, a spokesman for the state Department of Health.

Packages of Wild Harvest frozen spinach affected by the recall have a product code of 11535 50170, a sell-by date of Dec. 8, 2016, and a package code of L084WE.

The other three brands of frozen spinach involved in the recall — Cadia Organic Cut Spinach, Meijer Organics Chopped Spinach and Wegmans Organic Just Picked Spinach — are not stocked in Washington warehouses, according to the federal agency.

Once Twin Foods was alerted to the problem by its supplier, “we immediately put out notification to all the customers we supplied,” Twin City Foods spokesman Mark Hubbard said. Twin Cities learned of the problem on March 20, he said.

The national recall urges consumers to return the frozen spinach to the store where they bought it. The names of area stores that had stocked the recalled frozen spinach were not available on Wednesday.

The raw spinach was sent to Twin City Foods from Coastal Green Vegetable Co. of Oxnard, California, which contracts with growers throughout that state. “It’s harvested and comes to us raw, then we process it and freeze it,” said Paul Fanelli, a company spokesman.

It’s then sent to other companies for further processing, he said. “Some heat it, some have a cook step and some put it in bags with cooking instructions,” he said.

The company has temporarily suspended production and is trying to determine the source of the of the listeria contamination, he said. The problem was found through routine sampling that showed the company had shipped some products that tested positive for listeria, he said.

Sharon Salyer: 425-339-3486 or salyer@heraldnet.com.