Wolverine Packing Co. is recalling more than 167,000 pounds of ground beef shipped to restaurants due to possible E. coli contamination.

So far, 15 patients have been reported ill in Minnesota, with illnesses spanning Nov. 2-10, according to the United States Department of Agriculture Food Safety Inspection Service said Wednesday.

Fresh produce has a use-by date of November 14. Frozen products have a production date of October 22. The products bear an EST establishment number. 2574B in the USDA mark of inspection.

Items have been shipped to restaurants across the country, the FSIS said, which is concerned that some products may be in restaurant refrigerators or freezers. All products should be thrown away or returned and should not be consumed.

The Minnesota Department of Agriculture notified FSIS on Nov. 13 of illnesses in people who ate ground beef. On November 20, a sample of ground beef collected by the Minnesota Department of Agriculture tested positive for E. coli O157.

People infected with E. coli may experience symptoms such as severe stomach cramps, diarrhea, fever and vomiting. Symptoms of infection usually begin three or four days after swallowing the bacteria. Although most sick people recover without treatment within a week, others may develop serious kidney problems and require hospitalization.

CNN has reached out to Detroit-based Wolverine Packing Co. for a response.

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