Although Taco Bell says the independent lab it hired to look for the source of the E. coli outbreak found green onions to be the source, the Center for Disease Control and Prevention now says that its investigation is finding that probably no onions of any kind were connected to the E. coli outbreak.
The CDC says in its Web site's Tuesday update that 67 illnesses have been connected to the same strain of E. coli 0157, with 51 of those individuals hospitalized as a result.
The samples of green onions that the independent laboratory found to contain E. coli 0157 came up negative for the bacteria in federal tests. A sample of yellow onions from a Nassau County, New York Taco Bell tested positive for E. coli 0157, but with a DNA fingerprint that has not been seen in any ill individuals in the U.S.
The CDC says that although the outbreak's source has not yet been found, "it is presumed to be a contaminated food or foods." Ingredients consumed raw are under special scrutiny, the CDC says, but onions may be off the hook.
"This analysis is also demonstrating that onions of any type are probably not linked to this outbreak," CDC says.
Meanwhile, four members of the Senate - Hillary Clinton, D-N.Y., Charles Schumer, D-N.Y., Dick Durbin, D-Ill., and Frank Lautenberg, D-N.J. - sent a letter to the CDC, USDA, and the Food and Drug Administration, asking for a joint task force to look into the cause of the outbreak.