Infection-associated Hemolytic Uremic Syndrome or IA-HUS refers to a TMA that has an infectious etiology.  This TMA is associated with infection by Escherichia coli 0157:H7 which expresses Shiga toxin.  In these cases the TMA follows 5-7 days after the acute infection and the typical hemorrhagic colitis.  Infection with other subtypes of E. coli , Shigella, Salmonella, and Campylobacter can present similar.  In these cases patients will present with an acute TMA and renal failure, may be difficult to distinguish from CM-HUS and other forms of TMA.  Treatment for this form of TMA is largely supportive with the majority of patients recovering from their acute illness.