Eight cases of hemolytic-uremic syndrome in which no pathogens were isolated were diagnosed serologically by a passive hemagglutination assay and a verotoxin (VT; Shiga-like toxin) enzyme-linked immunosorbent assay (ELISA). The passive hemagglutination assay employed formalinized sheep erythrocytes sensitized with soluble native antigen or heat-treated antigen (lipopolysaccharide [LPS]) from Es...
