The Food and Drug Administration said during a Dec. 8 news conference that there is no conclusive evidence linking the recent E. coli outbreak traced back to Taco Bell restaurants to green onions. That announcement comes after the fast-food chain had pulled green onions from all of its 5,800 restaurants Dec. 5.

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

Christopher Braden, a medical epidemiologist at the Centers 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. "There are also quite a number of cases under investigation in numerous states," he said.

Acheson said a total of 169 cases are being investigated.

"What we haven't determined is what they ate at Taco Bell that was consistent," Acheson said.

For more information: www.fda.gov; www.cdc.gov