Questions and answers about Escherichia coli O157:H7, "one of hundreds of strains of the bacterium Escherichia coli [E. coli]," and a cause of foodborne illness. Topics include how this E. coli strain spreads, illness caused by the bacteria, prevention measures, and more. In English and Spanish. Provides a link to notices specifically about the 2006 E. coli O157:H7 outbreak from fresh spinach. From the Centers for Disease Control and Prevention (CDC).