How CDC Is Using DNA Technology in Suspected Chipotle E. Coli Outbreak Investigation

PHOTO: Signage hangs from a closed Chipotle restaurant in Portland, Ore., Nov. 2, 2015. PlayDon Ryan/AP Photo
WATCH Chipotle Speaks Out on E. Coli Outbreak, Restaurant Closures

As the E. coli outbreak believed to be linked to West Coast Chipotle restaurants grows, the U.S. Centers for Disease Control and Prevention announced it is using cutting-edge DNA technology to assist with the investigation.

At least 40 people in Washington and Oregon have been sickened with an E. coli infection, according to health officials, who said they believe the outbreak is likely linked to local Chipotle restaurants.

With the outbreak growing, the CDC announced Wednesday that the agency is helping local and state health departments in the search for the source of the outbreak, aided by cutting-edge technology that can test the DNA of the bacteria -- in essence, creating a family tree of the microbes.

CDC officials said they are trying "to determine the DNA fingerprint of the STEC O26 (E. coli) bacteria making people sick."

Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center, explained that it's key to know the DNA fingerprint of the bacteria so that health officials can identify the strain on food products and track down the source.

"They will try to trace back those ingredients [to see] which ingredient became contaminated where and when," he explained. "They may even then go back to those sources and trace potentially contaminated foods back to the very farm where it was produced."

Additionally, having the information in a national database means any new infections can quickly be identified, Schaffner said. As a result, seemingly unrelated outbreaks can quickly be connected and help officials track down the common source.

"Now the tech allows us to put all those bits and pieces together to recognize outbreaks that heretofore we could have never tied together," he explained. "It’s a powerful tool to knit all that together."

In addition to high-tech DNA testing, Schaffner said health officials will also rely on tried-and-true investigation techniques to find a source. Investigators will interview everyone who has been infected about their recent diet and also interview customers who did not get sick to determine which ingredients are the most likely culprit for the bacteria, Schaffner said.

There have been at least 14 hospitalizations related to this particular E. coli outbreak but no deaths, according to the CDC.

Chipotle issued a statement earlier this week saying they are taking multiple steps, including deep cleaning their restaurants and batch testing ingredients, to stop future outbreaks.

“The safety of our customers and integrity of our food supply has always been our highest priority,” Steve Ells, chairman and co-CEO of Chipotle, said in a statement Tuesday. “We work with a number of very fresh ingredients in order to serve our customers the highest-quality, best-tasting food we can. If there are opportunities to do better, we will push ourselves to find them and enhance our already high standards for food safety. Our deepest sympathies go out to those who have been affected by this situation and it is our greatest priority to ensure the safety of all of the food we serve and maintain our customers’ confidence in eating at Chipotle."