To determine the cause of a July 1996 outbreak of Escherichia coli O157:H7
among factory workers in Kyoto, Japan, we conducted cohort and case-control
studies. Eating radish sprout salad during lunch at the factory cafeteria
had been linked to illness. The sprouts were traced to four growers in Japa
n; one had been associated with an outbreak of E. coli O157:H7 among 6,000
schoolchildren in Sakai earlier in July.