(Dec. 11) Even though Irvine, Calif.-based Taco Bell pulled green onions from all of its 5,800 restaurants Dec. 5, after three samples tested at an independent lab showed signs of E. coli O157:H7, the Food and Drug Administration said during a Dec. 8 news conference that there is no conclusive evidence linking the outbreak to green onions.

David Acheson, chief medical officer for the FDA’s Center for Food Safety and Applied Nutrition, emphasized that there is no data to definitively implicate or rule out any food items linked to the outbreak. He said tests are being conducted on a number of food items besides green onions.

“Until we know definitively that green onions are the source, we want to keep the investigation broad and not focus down prematurely on one particular food item,” he said. “To date, neither state labs, nor FDA labs, nor CDC labs have been able to confirm that.”

He said the test results so far are preliminary, and the agency continued to work over the weekend.

Christopher Braden, a medical epidemiologist at the Center for Disease Control and Prevention, said there were 63 cases of E. coli in six states, New Jersey, New York, Pennsylvania, Delaware, South Carolina and Utah. Forty-nine people have been hospitalized, and seven have developed kidney failure. The illness range for the cases is from Nov. 20 to Dec. 2.

“There are also quite a number of cases under investigation in numerous states,” Braden said. “Information that we have would indicate that illnesses are still occurring, and we consider the outbreak to be ongoing.”

Acheson said a total of 169 cases are being investigated.

“That’s a combination of those who are associated with the outbreak and those who are suspect,” he said.

Unlike the outbreak involving fresh spinach where health officials were able to quickly determine that more than 80 people who were stricken with E. coli had eaten spinach, the only determining factor in this latest outbreak is that people ate at various Taco Bells.

“What we haven’t determined is what they ate at Taco Bell that was consistent,” Acheson said. “The evidence is pointing to a single restaurant chain mostly on the East Coast, but we’re not able to get further than that in terms of is it the green onions, is it the tomatoes, the lettuce or something else.”