Nestle briefly stopped production of chocolate chips at its Burlington, Wisconsin plant two weeks ago after company testing revealed Salmonella contamination in a batch produced April 22.
The company shut down the production line for thorough cleaning. Tests conducted on chocolate chip batches produced before and after the batch that tested positive were negative for Salmonella.
Nestle spokeswoman Laurie MacDonald told the local newspaper, the Journal-Times, that none of the contaminated chocolate chips left the plant. "That product remains under our control. All this routine testing is done all the time. "It's costly but necessary. Basically, the system worked."
A batch of chocolate chips produced at the same plant was found to be contaminated with Salmonella in mid-February, and two samples of Toll House refrigerated cookie dough made at a Virginia factory tested positive for E. coli bacteria in January. In both instances, the problem was identified before the product was distributed.
In 2009, a nationwide E. coli outbreak was traced to the consumption of Nestle Toll House cookie and brownie dough produced at the Nestle USA Danville, Virginia plant. Nestle temporarily laid off workers at its Danville plant, while investigators from the Centers for Disease Control and Prevention (CDC) and Food and Drug Administration (FDA) inspected the plant in an effort to determine where E. coli bacteria could have been introduced to the dough manufacturing process.
FDA officials later announced that three strains of E. coli O157:H7 had been isolated from cookie dough products, but that the investigation into the source of E. coli in the Nestle USA plant did not reveal the source of contamination.