Salad is often synonymous with wholesome consuming. Besides now, because the US grapples with an increasing outbreak of cyclosporiasis that’s sickened greater than 7,100 individuals in Michigan alone, doubtless brought on by iceberg lettuce equipped by Taylor Farms.
The truth is, leafy greens are steadily implicated in situations of foodborne sickness. There was a 2022 multistate E. coli outbreak tied to romaine served on Wendy’s sandwiches and 173 circumstances of norovirus linked to Illinois eatery D.C. Cobb’s. In 2021, BrightFarms recalled packaged salad greens bought in a number of states after 31 individuals bought salmonella. And in 2019, a complete of 167 individuals have been contaminated with E. coli after consuming romaine harvested from the Salinas Valley area in California. This is not even the primary cyclospora outbreak linked to lettuce: In 2020, Recent Categorical salad kits have been linked to greater than 700 circumstances of individuals bothered with the parasite.
The Facilities for Illness Management and Prevention estimates that produce is answerable for nearly half of the reported foodborne sickness circumstances, with leafy greens topping the listing. So what’s it that makes lettuce a significant supply of America’s foodborne tummy troubles?
One massive motive is just because a number of individuals eat it. Lettuce is the second-most-consumed vegetable within the US behind potatoes. (The newest outbreak ensures potatoes will stay the king of US veggies. Plus, french fries.) Wraps, subs, tacos, you title a quick meals sandwich and it’s nearly definitely bought lettuce on it. Salad-slinging chains are fixtures throughout the US. Grocery retailer coolers are stocked with salad kits, on prime of the unadorned heads of iceberg lettuce and containers of spinach.
These ready-to-eat salads and blends of spring combine pose a very acute danger as a result of they include a number of kinds of leafy greens, which may come from totally different farms and places. If one kind of lettuce within the combine is contaminated, it will possibly contaminate the entire bag. And since that contaminated lettuce will get packaged into tons and many bagged salad, it has the potential to unfold germs far and large.
How lettuce is grown may also expose it to a wide selection of pathogens. A 2025 examine by researchers at Cornell College who studied E. coli outbreaks in romaine lettuce discovered that plenty of contamination originates from irrigation with untreated floor water utilized via overhead spray irrigation programs. There are methods to decrease that danger, together with switching to irrigation programs that don’t straight contact the leaves, however that might require upgrades and downtime.
Lettuce’s satisfying crunch can be what makes it susceptible to pesky pathogens. Because it’s eaten uncooked—actually, who needs wilted lettuce?—there’s no alternative to prepare dinner off any lingering contaminants. Like different uncooked fruit and produce, leafy greens don’t undergo what’s referred to as a “kill step”—heating, pasteurization, or freezing—which is designed to eradicate pathogens through the meals manufacturing course of.
The feel of lettuce is a further consider its means to unfold illness.“Many lettuce sorts have plenty of crevices and folds,” says Jeanne Marrazzo, CEO of the Infectious Illnesses Society of America. “It’s very simple for these tiny pathogens to get in there.”
Even prewashing procedures at manufacturing amenities don’t all the time take away microbes, which may cling tightly to leaves. Within the case of cyclospora, the parasite has thick outer partitions, making it extremely immune to most meals sanitizers. Consultants say vigorous washing that includes scrubbing is the easiest way to do away with cyclospora.
“If you happen to do not wash these merchandise nicely, you are going to find yourself ingesting no matter is on the lettuce,” says Amira Roess, an epidemiologist at George Mason College.
