People who had eaten ice cream produced and sold at a farm in Antwerp developed Verotoxin-producing E.coli (VTEC). The pasteurized ice cream was served at two birthday parties and at the farm. Two strains of E. coli were involved in this outbreak E. coli O145 and E. coli O26. The identical strains of E. coli were found in leftover ice cream, in fecal samples from calves, and in samples of soiled straw at the farm. The pasteurization technique used by the farm appeared adequate. Because of the presence of the same bacteria on the farm, it seemed likely to the investigators that a farm worker could have contaminated the ice cream after it had been pasteurized.