People in at least 14 states caught a nasty strain of E. coli from tainted onions used in McDonald's Quarter Pounders, though the immediate danger has likely now passed.

The CDC said epidemiological data showed that slivered onions served at McDonald’s were the likely source of the outbreak.

While the Food and Drug Administration said Wednesday that the E. coli outbreak linked to McDonald’s “does not appear to be a continued food safety concern,” diners are stil