In February, a cluster of E. coli O157:H7 infections (4 cases) and E. coli O157:NM infections (3 cases) was detected in Minnesota. Illness appeared to be associated with eating alfalfa sprouts served at restaurants although two of the cases appeared to be caused by secondary transmission. Sprouts from four different restaurants identified by cases were traced back to the same distributor. Further traceback identified a single sprouter-grower plant in Minneapolis, and a single seed distributor. The distributor was located in Kentucky and had received the seed from Australia. The seed was distributed nationwide. The Minnesota Department of Health tested sprouts, irrigation water, and remaining seed at the sprout plant and found no evidence of E.coli. An outbreak of the same strain of E. coli O157:NM occurred in Colorado, in July, 2003; independent case-control studies linked infection in each outbreak with eating alfalfa sprouts that were traced to the same distributor. The Colorado sprouter reportedly complied with current FDA guidance; the Minnesota sprouter did not. There were deficiencies in disinfection of the seeds prior to sprouting.