1.8 million pounds of ground beef has been recalled after illnesses were reported in four states.

Detroit-based Wolverine Packing Company shipped the beef for use in restaurants in Massachusetts, Michigan, Missouri and Ohio.

The Food Safety and Inspection Service announced the recall after the beef tested positive for E. coli O157:H7. This is a Class 1 recall based on "a reasonable probability that the use of the product will cause serious, adverse health consequences or death," according to the USDA.

So far, 11 people have fallen ill in four states connected to this outbreak.

All recalled beef was produced between March 31, 2014 and April 18, 2014 and bear the establishment number EST. 2574B. It will have a production date code in the format "Packing Nos: MM DD 14" between "03 31 14" and "04 18 14". The complete recall list is here.

The USDA was first notified of illnesses May 12 and have been working with the Centers for Disease Control and Prevention.

The best way to avoid contamination is to safely thaw meat products and cook ground beef to an internal temperature of 160 degrees.

Read More:

• Michigan Firm Recalls Ground Beef Products Due To Possible E.Coli O157:H7 (USDA)
• E. Coli Fears Spark Recall Of 1.8 Million Pounds Of Beef (NPR)
• 1.8 million pounds of beef recalled, linked to E. coli (USA TODAY)