Contaminated lettuce has been linked to widespread outbreaks of cyclosporiasis in the United States this year, a disease that causes explosive diarrhea, vomiting and dehydration.
This is not the first time lettuce has been implicated. In 2018, an outbreak linked to McDonald's salads sickened more than 500 Americans in 16 states, federal data shows. Two years later, an outbreak linked to Fresh Express bagged salad affected more than 700 people, and an outbreak in 2022 was attributed to Caesar salad kits.
Lettuce has also been linked to Escherichia coli and Salmonella sprouts.
So why are leafy greens such a common culprit of foodborne illnesses? On the one hand, we eat a lot. Americans consume an average of 25 pounds of lettuce a year.
Second, lettuce is difficult to wash, which can leave it susceptible to any hitchhiking bacteria or parasites. “If you don't wash these produce well, you're going to end up ingesting whatever is in the lettuce,” said Amira Roess, an epidemiologist at George Mason University. CABLING.
Bacteria and parasites can hide deep in the crevices between lettuce leaves, and it doesn't help that lettuce grows close to the ground. The closer fresh produce is to the ground, the more likely it is to come into contact with contaminated water that can spread the virus. cyclospora widely parasite.
Contaminated water is the likely source of most large outbreaks, including this one, experts said. The New York Times last week.
“Many products would have to be watered with a lot of water that was contaminated by many cyclospora “It's hard to see this number of cases,” said Keith Schneider, a food safety professor at the University of Florida.
Due to the hard but fragile exterior of lettuce leaves, it can be more difficult to clean than smooth-skinned products.
Broken leaves are also a problem, said Barbara Kowalcyk, director of the Institute for Food and Nutrition Security at George Washington University. TIME.
He explained that this is “the way bacteria get in.”
Relying on pre-washed lettuce is also not necessarily safe, as it may not eliminate microbes attached to the leaves, the University of Connecticut Extension said.
Lastly, we eat raw lettuce in sandwiches and salads. That's a big part of the problem. Heating products to a temperature of 158 degrees Fahrenheit is the only thing that kills the cyclospora parasite.
Cooking may also be effective against some strains of Salmonella and Escherichia coliif done well.
Parsley and cilantro are reported to be linked to recentcyclospora cases in North Carolina, according to the New York Post. Herbs have many of the same problems as lettuce. We eat them raw, they grow close to the ground and are often difficult to clean.
“Because these herbs can commonly be consumed unwashed or without a 'killing step,' such as cooking, there may be an increased risk of human illness if microbial hazards are present,” the FDA warns.
The best case might be to avoid these potentially contaminated foods for now.
“People usually laugh when they hear the phrase 'explosive diarrhea,' but for the people who experience it, there's nothing funny about it,” said Darin Detwiler, professor emeritus at Northeastern University. serious meals.
“Behind every reported case is a person whose life was unexpectedly cut short simply because they ate food they believed to be safe.”
