Here is another perspective on non-O157:H7 that seems to indicate that they cause illness, but less severe illness that E. coli O157:H7.  That being said, it is also quite likely that the severe illnesses related to non-O157:H7 are under counted due to a lack of surveillance.  This presentation also did not take into account the Oklahoma E. coli O111 outbreak that sickened over 300, dozens with severe Hemolytic Uremic Syndrome and one death.  Perhaps we could focus on, test for and list as adulterants, the top 6 reported non-O157 STEC in the US (all of these have been associated with HUS according to the CDC) – O26, O111, O103, O121, O45, and O145?