This review deals with the epidemiology and ecology of enterohemorrhagic Escherichia coli (EHEC), asubset of the verocytotoxigenic Escherichia coli (VTEC), and subsequently discusses its public health concern.Attention is also given to the outbreak strain O104:H4, which has been isolated as causative agent of thesecond largest outbreak of the hemolytic uremic syndrome worldwide, which started in Germany in May2011. This outbreak strain is not an EHEC as such but possesses an unusual combination of EHEC andenteroaggregative E. coli (EAggEC) virulence properties.