RECALL: Bagged lettuce - WKOW 27: Madison, WI Breaking News, Weather and Sports

SALINAS, Calif. (WKOW) -- A California lettuce grower has expanded a recall of some bagged salads after routine sampling detected traces of listeria.

The recall by River Ranch Fresh Foods of Salinas initially included lettuce shipped to California and Colorado. But, the company expanded the recall to the entire nation on Monday.

The bagged salads are sold under the names River Ranch, Farm Stand, Hy-Vee, Marketside, Shurfresh, The Farmer's Market, Cross Valley, Fresh n Easy, Promark, and Sysco.

The recalled salad bags have "best by" dates between May 12 and May 29 or Julian dates of 118 and 125. The code date is typically located in the upper right hand corner of the bags.

Symptoms of listeria infection include high fever, headache and neck stiffness. At this point no illnesses have been reported.

Consumers with the recalled products should not eat it and are urged to return it to the place of purchase for a full refund. Questions about the recall should be directed to the River Ranch at their 24-hour customer service center at 1-888-624-2569.

For more information on the recall, including a full list of the recalled items, click here.