Salad is normally 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, probably attributable to iceberg lettuce supplied by Taylor Farms.
In reality, leafy greens are continuously 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 obtained Salmonella. And in 2019, a complete of 167 individuals had been contaminated with E. Coli after consuming consuming romaine harvested from the Salinas Valley area in California. This is not even the primary cyclospora outbreak linked to lettuce: In 2020, Contemporary Categorical salad kits had been linked to greater than 700 circumstances of individuals stricken 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 checklist. So what’s it that makes lettuce a significant supply of America’s foodborne tummy troubles?
One large purpose is just because plenty 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 identify a quick meals sandwich and it’s nearly actually obtained 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 forms of leafy greens, which may come from totally different farms and areas. If one sort of lettuce within the combine is contaminated, it could possibly contaminate the entire bag. And since that contaminated lettuce will get packaged into tons and plenty of bagged salad, it has the potential to unfold germs far and large.
How lettuce is grown can even expose it to a wide selection of pathogens. A 2025 study by researchers at Cornell College who studied E. Coli outbreaks in romaine lettuce discovered that lots of contamination originates from irrigation with untreated floor water utilized by overhead spray irrigation programs. There are methods to decrease that danger, together with switching to irrigation programs that don’t immediately contact the leaves, however that might require upgrades and downtime.
Lettuce’s satisfying crunch can be what makes it liable to pesky pathogens. Because it’s eaten uncooked—actually, who needs wilted lettuce?—there’s no alternative to cook 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 remove pathogens throughout the meals manufacturing course of.
The feel of lettuce is a further think about its potential to unfold illness.“Many lettuce varieties have lots of crevices and folds,” says Jeanne Marrazzo, CEO of the Infectious Ailments Society of America. “It’s very simple for these tiny pathogens to get in there.”
Even prewashing procedures at manufacturing amenities don’t at all times take away microbes, which may cling tightly to leaves. Within the case of cyclospora, the parasite has thick outer partitions, making it extremely proof against most meals sanitizers. Specialists say vigorous washing that includes scrubbing is one of the best ways to do away with cyclospora.
“Should you do not wash these merchandise effectively, you are going to find yourself ingesting no matter is on the lettuce,” says Amira Roess, an epidemiologist at George Mason College.
