Federal health officials concluded their investigation into an E. coli outbreak linked to McDonald’s Quarter Pounders, determining that slivered onions served on the burgers were the likely culprit.
"Over the last few months, we have seen a stunning number of outbreaks, and I know because I have been doing this work since the 1993 Jack-in-the-Box E. coli Outbreak," said William "Bill" Marler.