Nestle recalled the cookie dough on June 19 after the Centers for Disease Control and Prevention (CDC) connected it with an E. coli outbreak that has sickened at least 72 people across 30 states. Tests later found E. coli in a sample of refrigerated cookie dough produced at the plant, but it has now emerged that the E. coli strain found in the sample does not match the illness strain. The FDA has concluded that the dough contained more than one strain of E. coli but has remained baffled as to the source of the bacterium, which is found in cattle intestines.
None of the main ingredients in the dough is known to host E. coli.
The FDA’s assistant commissioner for food safety David Acheson said that the agency is unlikely to discover the source despite conducting extensive tests at the Nestle plant, as well as probing its ingredient suppliers.
“This will be one of those situations where we won’t definitely know what went wrong,” said Acheson.
However, he suggested that flour was the most plausible source of E. coli as it is a raw agricultural ingredient that could have been contaminated by animals when it was still in the field. This led health officials to inspect Nestle’s flour supplier after tests at the Danville plant did not find the bacterium.
Nestle said that all of its machinery was dismantled and tested over the course of a week-long inspection which uncovered two minor food safety issues involving condensate on an implement used for scraping dough from a mixer, and a valve which required a smoother surface for ease of cleaning.
“Neither of these observations is believed to have any relationship to the presence of E. coli O157:H7 found in the retained production sample,” Nestle said. “…Both of the observations have been corrected.”
The company said that it has also discarded and replaced all of the ingredients that had been stockpiled since the recall was announced and added that all its newly produced cookie dough products will be marked as coming from a ‘new batch’.
General Manager of Nestle’s baking division Paul Bakus said: "We are very concerned about those who have become ill from E. coli O157:H7 and deeply regret that this has occurred."