Romaine lettuce has sickened dozens in a recent E. coli outbreak. Pictured: romaine lettuce

People are still getting sick after eating romaine lettuce tainted with E. coli.

The Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) said Wednesday that the outbreak has sickened 23 more people, bringing the total to 122 cases identified since April 10. What’s especially concerning is that more than half of those who've gotten sick have been hospitalized, and one person has died.

The CDC and the FDA also said it's possible that the tainted lettuce is still on store shelves. That's because much of the nation's romaine production only recently shifted to California from Yuma, Ariz., which the agencies identified as the source of the outbreak.

Given this, and how tough it is for consumers to determine where romaine was grown, Consumer Reports continues to say consumers shouldn't eat any type of romaine lettuce for now.

“This is a pretty bad outbreak, and becoming infected with this strain of E. coli can have serious consequences,” says James E. Rogers, Ph.D., director of food safety research and testing at Consumer Reports.  

Since plenty of supermarkets and restaurants are selling and serving romaine lettuce, consumers may still be wondering whether it’s safe to eat it. We’ve compiled some answers to the most pressing romaine questions you might have now.

What Is E. Coli Anyway?

E. coli is a group of bacteria that normally live in the intestinal tract of people and animals. Most strains of this bacteria do not make people sick—in fact they are essential to digestion. But certain strains cause not just typical food poisoning symptoms, such as diarrhea and vomiting, but can cause organ failure.

More on this E. coli outbreak

The O157:H7 strain involved in this romaine outbreak is what’s known as a Shiga-toxin producing E. coli (STEC). This toxin can cause severe illness, including bloody diarrhea and, in certain cases, hemolytic uremic syndrome, a form of kidney failure that can be fatal.

E. coli O157:H7 is often associated with tainted meat (especially ground beef), but many of the outbreaks in recent years have involved plant foods such as soy nut butter, flour, alfalfa sprouts, spinach and leafy greens. In addition to being the source of the most recent outbreak, romaine was implicated in a late 2017 E. coli outbreak.

The bacteria often contaminates plants when animal or, more rarely, human waste—which can harbor E. coli—ends up in growing fields, says CR's Rogers. For instance, a 2006 E. coli outbreak was believed to be linked to waste from feral pigs that invaded some California spinach fields. There can also be cross-contamination, if tainted lettuce comes into contact with clean lettuce at a processing facility.

Why Are so Many People Getting Sick?

“This appears to be a particularly virulent strain,” says Rogers.  

It may also be that the lettuce is heavily contaminated with E. coli. The CDC says that the number of people who have been hospitalized is significantly higher in this outbreak than in others—51 percent versus the typical 30 percent. Fourteen people have developed hemolytic uremic syndrome—the rare but life-threatening  condition linked to E. coli O157:H7 that affects the blood vessels and can lead to kidney failure.

How Do I Know If I Have E. Coli?

Symptoms of infection with E. coli O157:H7 include severe stomach cramps, diarrhea (often bloody), and vomiting. Some people may have a slight fever. The CDC recommends seeing a doctor if you have a high fever, bloody diarrhea, or severe vomiting, or if diarrhea lasts longer than three days.

Isn’t Just Bagged Romaine the Problem?

The CDC’s initial advisory on April 10 only warned against consuming chopped romaine, but the agency has since expanded its advice. Avoid all forms of romaine lettuce: whole heads and hearts; romaine in a clamshell or bagged; alone or mixed with other greens—unless you’re sure it isn’t from Yuma.

Can I Eat the Romaine If the Supermarket Says It Isn't From Yuma?

Some chains like Kroger, Meijer, and Panera Bread have announced—either through signs, tweets, or public statements— that they’re no longer selling or serving romaine products from the Yuma area. If that’s the case at your market, you can feel pretty confident that it’s true. But without this kind of explicit assurance from a retailer or restaurant, just steer clear of all romaine for now; it is often quite difficult to figure out where lettuce was grown (whether you’re at a restaurant or a supermarket).

“It’s unreasonable to expect the consumer to figure this out,” says Rogers. “I went to my local supermarket recently and I couldn’t tell where any of the romaine or salad mixes were sourced by checking the packages.”

Is Romaine From Yuma Still Being Shipped to Stores?

The romaine lettuce growing area has shifted from Arizona to California. While the FDA said this week that it received confirmation from the Arizona Leafy Greens Marketing Agreement  that no romaine lettuce from the Yuma region is currently being shipped to market, it is possible that Yuma-grown romaine could still be in stores or restaurants.

“Romaine is a hearty green, and could stay fresh for up to four weeks after harvest,” says Jean Halloran, director of food policy initiatives at Consumers Union, the advocacy division of Consumer Reports. “Romaine from Yuma could still be on the shelves through mid-May,” she adds.

Is It Okay to Eat Salad Mixes If They Don’t Say Romaine on the Packaging?

Not necessarily. Certain salad mixes, with names like “Asian Lettuce Blend” or “Spring Mix” sometimes don’t list the exact lettuces they contain.

Additionally, romaine can often look like other lettuces. When in doubt, steer clear. Other lettuces and greens aren’t part of the outbreak, though, so you can buy a container of arugula, a head of butter lettuce, or a bunch of spinach to get your salad fix.

Is Organic Romaine Safe?

Not necessarily. The CDC has given no indication whether this outbreak came from conventionally grown or organic romaine. There is also nothing inherent in the organic growing process that protects the plant from foodborne bacteria.

Won’t Rinsing the Lettuce Get Rid of Any E. Coli Bacteria If It’s There?

No. Washing has proven to be ineffective in removing E. coli from leafy greens.

Has the CDC or the FDA Identified a Brand or Farm to Avoid?

On April 27, federal investigators announced the name of one Yuma grower that has been identified as providing the romaine that sickened eight inmates at a prison in Alaska—Harrison Farms. The last romaine was harvested there on March 16.

However, the investigators caution that dozens of other farms are still being investigated in the Yuma region. Matthew Wise, deputy branch chief for outbreak response at the CDC, says other farms may have shared a water source or a processing facility with Harrison. Wise adds: "There are many legs to chase" in this outbreak.

The agencies both say no other supplier or brand has yet been identified. But CR's Rogers says the agencies are exceedingly careful not to prematurely assign blame.

“When an outbreak is this serious, you wish they’d be a little more forthcoming in releasing information,” he says.

Editor's Note: This story was updated on May 2 to reflect new information on the number of people sickened in this outbreak.