Wolverine Packing Co., a Detroit establishment, is recalling about 1.8 million pounds of ground beef products that may be contaminated with E. coli O157:H7, the USDA’s Food Safety and Inspection Service (FSIS) announced today.

FSIS was notified of E. coli O157:H7 illnesses on May 12, 2014. Working in conjunction with public health partners from the Centers for Disease Control and Prevention (CDC), FSIS determined that there is a link between the ground beef products from Wolverine Packing and this illness cluster.

Based on epidemiological and traceback investigations, 11 case-patients have been identified in four states with illness onset dates ranging from April 22, 2014 to May 2, 2014. FSIS continues to work with our state and federal public health partners on this investigation and provide updated information as it becomes available.

The ground beef products were produced between March 31, 2014 and April 18, 2014. For a full list of products, click here.

The products subject to recall bear the establishment number “EST. 2574B” and will have a production date code in the format “Packing Nos: MM DD 14” between “03 31 14” and “04 18 14”. These products were shipped to distributors for restaurant use in Massachusetts, Michigan, Missouri and Ohio. There was no distribution of the products to the Department of Defense, the National School Lunch Program, or catalog/internet sales.

Factors that can contribute to the size of the recall include potential contamination of additional products due to a lack of microbiological independence between lot production, as well as a deficiency in supportive record-keeping by distributors.