E. coli: Why you had to throw out that romaine lettuce

Romaine lettuce
Romaine lettuce.
Steve Campbell | Houston Chronicle via AP

The food-borne illness E. coli is back in the news after the bacteria caused a rash of food poisoning, linked to romaine lettuce grown in Yuma, Ariz.

The Centers for Disease Control and Prevention said nearly 100 people in 22 states have been sickened in connection with this outbreak.

Just what is this nasty bacteria?

Create a More Connected Minnesota

MPR News is your trusted resource for the news you need. With your support, MPR News brings accessible, courageous journalism and authentic conversation to everyone - free of paywalls and barriers. Your gift makes a difference.

E. coli is actually the most common bacteria that lives in our guts, said MPR News' regular medical analyst Dr. Jon Hallberg. But there are different strains of it — most harmless, but some that cause diarrhea, cramps and vomiting.

How did it get on the lettuce?

"The reality is that it's a fecal contaminate," Hallberg said. The CDC is still trying to determine the exact cause but it's likely animal feces that got into water was either sprayed on the lettuce or brought in via flooding.

How dangerous is it and how is it treated?

Less than 10 percent of people exposed to E. coli can develop hemolytic-uremic syndrome, which causes blood vessels to break down and can lead to kidney failure. Doctors are cautioned against using antibiotics for this sickness, so most of the time treatment includes keeping the patient hydrated while watching for those more severe reactions, Hallberg said.