A multistate epidemiologic investigation into an outbreak of E. coli O157:H7 infections began in Ohio. The data indicated a significant association between illness and eating ground beef purchased at one of several Kroger Company stores in Michigan and Ohio. A traceback investigation of the ground beef from Kroger Company revealed that the beef originated from Nebraska Beef, Ltd., a beef processor. A recall for Kroger Company ground beef was issued for the ground beef sold in Michigan and Ohio. On July 3, Kroger Company expanded the recall to include ground beef sold at all of its stores. On June 30, a recall of 531,707 pounds of ground beef from Nebraska Beef Ltd. was announced. On July 3, Nebraska Beef Ltd expanded the June 30 recall to include all beef manufacturing trimmings and other products intended for use in raw ground beef produced between May 16 and June 26, totalling approximately 5.3 million pounds. Also see outbreak report for Barbeque Pit Restaurant in Georgia. Nebraska Beef would later be implicated, in July, in another outbreak of E.coli O157:H7. The strain of E. coli O157:H7 in that outbreak was a different PFGE pattern than the strain identified in this outbreak.