Background: Enterohemorrhagic Escherichia coli (EHEC) O26 has emerged as a significant cause of hemolytic-uremic syndrome (HUS). The source and the vehicle of contamination with EHEC O26 are not often identified. We report two Austrian cases of HUS due to E. coli O26:H- affecting an 11-month-old boy and a 28-month-old girl in which transmission through unpasteurized cow's milk was positively identified.
Methods and results: Using automated ribotyping and pulsed-field gel electrophoresis (PFGE), the isolates (which yielded the virulence genes stx2, eae, and hly) were indistinguishable from each other. An epidemiologic investigation revealed that the children had stayed in the same hotel. Both patients had consumed unpasteurized cow's milk from the breakfast buffet. Fecal samples were taken from the cows of the farm producing the incriminating milk, and one of three cattle EHEC O26:H- isolates had a PFGE pattern indistinguishable from that of the patients' strains.
Conclusions: These two cases of E. coli O26 infection illustrate the hazards associated with the consumption of raw milk, and underline the importance of microbiological diagnostic approaches able to detect sorbitol-fermenting, non-O157 EHEC.