 Hemolytic uremic syndrome HUS is defined by the combination of microangiopathic hemolytic anemia, thrombocytopenia and acute renal failure. The underlying lesion is thrombotic microangiopathy TMA affecting arteriole and capillary walls, with endothelial cells swelling and detachment and thrombi obstructing vascular lumina. Post- diarrheal HUS DHUS is induced by an infection due to E. coli STEC producing a Shiga -like toxin Stx which is responsible of TMA. Serotype O157:H7 represents 63-97 of STEC causing DHUS. Other serotypes frequently implicated in outbreaks are O26:H11, O103:H2, O111:H8, O145:H28 Mariani - Kurkdjian P et al, 2001 Espié et al, 2008. 