California could be source of romaine lettuce tainted with E. coli, FDA says

The FDA is looking at California as a potential source of romaine lettuce tainted with a potentially deadly strain E. coli. Health officials said romaine lettuce should be removed from all supermarket shelves and restaurant menus until they can determine the source of the new outbreak. But, as Anna Werner reports, tracking down the source of the contaminated produce is quite difficult.

The potentially deadly strain of the bacteria has sickened 32 people in 11 states since October. Nearly a third of the cases are in Los Angeles County.

Scott Horsfall, the CEO of the California Leafy Greens Marketing Agreement, said most of the romaine on the market when the outbreak began was grown in his state.

"Given the harvest cycle at that time, I think there's a good possibility that it came from California, yes," Horsfall said.

But he also said finding the exact farm will be difficult because it takes about two to three weeks for investigators to confirm an E.coli outbreak is underway.

"So by the time they're actually doing trace-back, there is no packaging left, there's no product left," Horsfall said.

An important clue for investigators is the bacteria's DNA. It's very similar to the E.coli strain that caused a still unsolved outbreak in 2017.

"If you look at the map of illness onsets from last year, it is very similar to this recent outbreak ... because these two are related, we have really more clues to go by now in terms of where people got sick and the timing involved," Horsfall said.

The CDC said about 48 million people get sick from foodborne illnesses every year – 46 percent of them from eating leafy vegetables and other produce.

Cooking kills most germs found in food, but because romaine lettuce is usually eaten raw that's not really an option. The CDC says just throw it out, it's not worth the risk.