First things first: If you’re still eating romaine lettuce, stop. The year’s first major outbreak of a foodborne illness started in mid-March, when cases of E. coli infection were linked to romaine. Over the past few weeks, the ongoing outbreak has caused a nationwide panic, as retailers like Costco, Kroger, and Walmart pulled lettuce from their stores, the CDC issued warnings, and the number of documented cases of E. coli infection doubled, then tripled. Here’s everything you need to know about what’s happening.
How widespread is the romaine-lettuce contamination?
As of the CDC’s last reporting, on April 20, there have been 53 documented cases in 16 states, resulting in 31 hospitalizations. The infection has hit people from New Jersey to Alaska, but Tamika Sims, a microbiologist and director of food technology communications at the International Food Information Council, says the number may actually be much higher.
The outbreak is so widespread in part because of “the popularity of [romaine lettuce],” she says, “which also means it’s being produced in massive amounts. Right now we’re talking 16 states, but that’s just what’s been reported. A lot of the time cases of foodborne illness in hospitals don’t get documented, or linked to a specific outbreak, because people don’t remember what they did or didn’t eat. So it’s in 16 states, but it could actually be more.”
Does this mean all brands of romaine lettuce are unsafe?
While investigators haven’t yet determined the exact source of the E. coli contamination, they have linked the contaminated lettuce to the area of Yuma, Arizona. That doesn’t mean the problem is contained, though: the Yuma area produces about 90 percent of all the leafy vegetables — including all the romaine — grown and consumed in the United States between November and March.
That’s also made it difficult for investigators, retailers, and shoppers to determine which specific brands of lettuce have been affected. Lettuce grown on one Yuma farm might ultimately be packaged by any number of brands, as whole heads, chopped, or tossed with other lettuce in a salad mix. And many product labels don’t include information about the growing region, so it’s tough to be sure. Cases associated with this outbreak have been linked to both lettuce bought in grocery stores and lettuce eaten in restaurants.
As far as the source of the contamination, we’re still not sure. “At this time,” the CDC said in a statement, “no common grower, supplier, distributor, or brand has been identified.” Sims says an outbreak of this magnitude is typically the result of contamination in a product or resource that’s used widely, perhaps by multiple growers. “This isn’t about one person with dirty hands,” she says. “This is a bigger issue. It could’ve been the fertilizer, the water source — contamination can happen at a lot of steps in the supply chain.”
If I know my romaine isn’t from Yuma, is it okay to eat?
Yes, if you’re positive of its source. If there’s any uncertainty at all, though, the CDC advises staying away. The same goes for any lettuce you’re not sure is romaine, and salad mixes whose contents are unknown.
What exactly is E. coli?
It’s a bacteria associated with the lower intestines of many animals, including humans. Farm animals, household pets, and people are all walking around with E. coli bacteria working in our guts.
“There are lots of different strains of E. coli,” explains Kristin Levin, a medical resident at University of Louisville Hospital. Many strains are harmless, and they’re actually important to a healthy microbial environment in the intestines.
But others, called pathogenic strains, are less innocuous. “The one causing this outbreak is E. coli 0157:H7,” Levin continues. “It’s what we call an EHEC, or enterohemorrhagic. This strain is really not good for you.”
The bacteria E. coli 0157:H7 produces something called Shiga toxin, which is what makes you sick. Enterohemorrhagic means it causes hemorrhagic colitis, a condition that — well, it isn’t pretty.
“When you ingest the bacteria, it adheres to the walls of the intestines and releases the Shiga toxin,” Levin says. “It invades the cells and basically makes them explode, destroying your intestinal lining. It can invade all the way to the vasculature of the intestines, and that’s what gives you bloody diarrhea. It also causes abdominal cramping and vomiting.”
Is an E. coli infection deadly?
It’s pretty bad, but for most otherwise healthy people, it’s not life-threatening. And that’s good, because there’s really no cure for an E. coli infection.
“You can’t really do anything but supportive care,” Levin says. “You just drink as many liquids as you can so you don’t become dehydrated, try to continuously replenish your electrolytes, and ride it out.”
In these cases, it typically takes about a week for your immune response to kick the infection and for the cells of your intestinal wall to regenerate.
For people who are more at-risk, including children, the elderly, and those with an already-compromised immune system, things can get a lot worse. In 5 to 10 percent of cases, E. coli 0157:H7 can cause a condition called hemolytic uremic syndrome, which can lead to kidney failure.
“An infection like this can be life threatening if not treated in a hospital,” Levin says. “So it’s very important for people who think they might be ill to see a doctor, particularly young children, people on chemo, or those with underlying chronic conditions, AIDs, Lupus, or anyone who’s on steroids chronically. They don’t have the immune response they need to fight the bacteria, and it can be life threatening.”
Even healthy teenagers and young adults are at risk of developing complications, not because of the bacteria itself, but as a result of the infection’s symptoms.
“With a lot of people who get really sick, it’s not really from the toxin itself,” Levin says. “Most people will have bad diarrhea, drink some Gatorade and be okay. But dehydration or electrolyte imbalances can make you really ill, and land you in a hospital.”
If you think you may have contracted E. coli, you should see a doctor right away, Levin says, but especially if you feel chest pain or dizziness. And the three major symptoms of hemolytic uremic syndrome, she says, are dizziness, decreased urination, and a rash.
How will I know if I’m going to get sick?
By the time you have symptoms, it’s too late. Unlike run-of-the-mill food poisoning, which can hit within hours of consuming tainted food, E. coli infections take a bit longer to gestate.
“With most food poisoning, you feel sick and you can say, ‘Oh, it’s that Chinese food I ate at lunchtime,’” Levin says. “In this case, the bacteria needs a few days to attach to the intestinal wall, so when you start to feel sick it’s really because of what you ate three to four days ago.”
So how do I keep myself from getting sick?
Simple: until the CDC gives the all clear, and unless you can guarantee beyond all doubt that it’s not from the Yuma, Arizona, area, do not eat romaine lettuce. Even if you’re careful, the tiniest contamination can make you sick.
“Certainly with something like romaine, which is eaten raw, the risk is even higher,” Sims says. “You don’t cook it, so there’s no opportunity for heat to kill the bacteria. And even if you wash the lettuce as thoroughly as anyone could, you won’t eliminate the risk. You should not play the odds.”
After all, the amount of E. coli 0157:H7 it takes to hurt you is minuscule. “We call the amount of bacteria it takes to make you sick the ‘infectious dose,’” Levin says. “This bacteria has a very low infectious dose. You don’t have to eat a whole salad, just one bite. The bacteria replicates rapidly, so you really don’t need much.”
When will I be able to eat romaine again?
The good news, at least according to Sims, is that these types of outbreaks typically don’t last too long.
“They were able to trace it to one particular area very quickly,” she says. “I think that’s a great thing as far as showing the traceability of products. It’s a matter of time before the source is determined, and the problem is resolved.” So, fortunately, you won’t have to give up Caesar salad forever. But for the time being, just stick to the side of fries.