STX2 and hemolytic-uremic syndrome: We found that 8 (80%) of 10 isolates from HUS cases carried the stx2a gene; however, statistical analysis showed that the presence of stx2a was not significantly associated with HUS (OR, 4.4444; P = 0.0678) or hospitalization (OR, 2.0829; P = 0.0986), suggesting that other features of 1c3 and/or host factors are likely to be important in the development of severe complications of infection.