WASHINGTON — The 1.8 million lbs of ground beef manufactured by Wolverine Packing Co., Detroit, may have been distributed nationwide, according to the U.S. Department of Agriculture’s Food Safety and Inspection Service. The F.S.I.S. initially said the recalled product was distributed to four states: Massachusetts, Michigan, Missouri and Ohio.

But in an update posted on the F.S.I.S.’s web site, the agency said “upon further investigation, F.S.I.S. now believes the product was sent to distribution centers nationwide.”

The full list of the products subject to the recall may be viewed by clicking here: Wolverine Packing recall list. Products included in the recall were manufactured between March 31 and April 18, and distributed for use by food service operators.

The F.S.I.S. was notified of E. coli O157:H7 illnesses on May 12. Working in conjunction with the Centers for Disease Control and Prevention, F.S.I.S. officials determined that there was a link between the ground beef products from Wolverine Packing Co. and the illness cluster. Based on epidemiological and trace-back investigations, 11 case-patients have been identified in four states with illness onset dates ranging from April 22 to May 2.