By Sandy K. Johnson

What happens when big data meets microbiology? In the case of food contamination and people who are sickened by it, DNA sequencing has been a game-changer.

Dr. Robert Tauxe, director of the food-borne diseases division at the Centers for Disease Control and Prevention, said the cost and speed of sequencing DNA from bacteria has dropped from hundreds of thousands of dollars and a year’s time to $100 and a few hours.

That means all the difference when the CDC and health departments are investigating the sources of food-borne illnesses, which sicken 48 million Americans each year and turn deadly for 3,000.

Close genetic similarity means greater confidence that a group of infections may share a common origin, allowing CDC investigators to be more focused, Tauxe told National Press Foundation fellows.

As an example, he cited the E. coli outbreak from romaine lettuce in 2018 that killed five people and sickened 210 others in 36 states. Investigators were able to trace the outbreak to lettuce fields along an irrigation canal near Yuma, Arizona.

Tauxe looked into his crystal ball and described what future food-borne illness outbreaks might look like.

They may be much broader – i.e., not just in counties or states but across national borders. They may last much longer than current outbreaks. And they may be antibiotic-resistant, although Tauxe is confident that gene sequencing can identify “new weird genes appearing for the first time.”

Tauxe said CDC investigators have something in common with journalists – “that relentless questioning ability and pursuit of the facts.”