What is it about romaine lettuce that leads to seemingly frequent contamination? It seems that romaine has been recalled several times since 2010, including twice this calendar year. Does anything similar happen with other types of greens? It seems not, but maybe it’s just selective memory.
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Kind of a side question: Food recalls in general seem to be MUCH more frequent today than they were 20+ years ago. Is that correct? And if correct, that’s likely due to the obvious answers: more advanced data collection/processing, the Internet/social media getting the word out more effectively, etc.?
Leafy greens are the problem, as they are typically eaten raw and the industry has been fighting putting in expensive testing and supply chain tracking.
Here is the FDA report from the spring outbreak that will explain some of the issues.
Thanks, rat avatar. Does there seem to be a difference in recall frequency among leafy-green types? Seems like romaine gets recalled a lot more than iceberg, arugula, leaf spinach, etc.
Perhaps the structure of different leaves is a factor? You’d imagine that something crinkly would be more difficult to wash thoroughly, and would provide nooks and crannies for bugs to thrive?
Same. Maybe snails would be bad too. This is why I never, EVER eat bagged salad or whatever that claims it’s already washed and ready to eat without washing it again, or sometimes picking through the lettuces and tossing the slimy bits.
*But six months before people were sickened by the contaminated romaine, President Donald Trump’s FDA – responding to pressure from the farm industry and Trump’s order to eliminate regulations – shelved the water-testing rules for at least four years.
Despite this deadly outbreak, the FDA has shown no sign of reconsidering its plan to postpone the rules. The agency also is considering major changes, such as allowing some produce growers to test less frequently or find alternatives to water testing to ensure the safety of their crops.
The FDA’s lack of urgency dumbfounds food safety scientists.
The lack of urgency from the FDA mirrors Trump’s own. He often refuses to acknowledge the findings of his own administration, be it on economics or climate change when they don’t say what he wants them to say. In fact, he spent Thanksgiving eating Caesar salad despite the CDC’s recall warning.*
Animal waste entering the fields through irrigation and flooding is the main cause. Secondary is human waste from the field workers who often don’t have access to toilet facilities.
Some people have decided to risk eating after the recall because they believe it is only a problem for those who are compromised. While those individuals may be more susceptible the risk is not restricted to the young, old, or with compromised immune systems.
As this type wasn’t even recognized until 1982 we simply wouldn’t know about cases directly tied to E. coli O157:H7 before then.
From Wikipedia (follow the links if you don’t trust Wikipedia itself):
“While it is relatively uncommon, the E. coli serotype O157:H7 can naturally be found in the intestinal contents of some cattle, goats, and even sheep.[10] The digestive tract of cattle lack the Shiga toxin receptor globotriaosylceramide, and thus, these can be asymptomatic carriers of the bacterium.[11] The prevalence of E. coli O157:H7 in North American feedlot cattle herds ranges from 0 to 60%.[12]”
I think this is unlikely in the case of these E coli infections. We contain a lot of benign E coli in our gut, obviously. But I don’t think humans can usually carry O157 asymptomatically. So the origin would probably be farm animals. Of course, at a late stage after a mass outbreak sick humans could be spreading it among themselves, but that would be a secondary effect.
A lot of humans do apparently carry various strains of Giardia asymptomatically, though. There have been extensive studies of water in the Sierra Nevada, of particular relevance to backpackers. Standards of hygeine in the backcountry can be poor, and I remember reading estimates that around 90% of Giardia infections come from hiking partners rather than water sources. Don’t shake hands with strangers that you meet while backpacking!
I heard a food safety expert talking on the CBC radio about this; he mentioned several previous outbreaks had been traced to certain areas - one even was irrigating from the same canal where the field across from the farm was a large dairy farm. the biggest culprit (he says) is E Coli from animal waste washing into the water source for irrigation. One good rainstorm can contaminate the whole irrigation source, and as others mention, we don’t cook it, so unless it is really well washed (if possible) I will be covered since the irrigation water is sprayed on it.
My guess would be that there’s a lot more Romaine than other lettuce types. It’s thick and hardy, so it ships better and lasts longer than most lettuce, letting the industrial supply chain really get into gear. Lots of prepackaged salads use romaine for that reason.
More farms means more possibilities for contamination. More product means it’s a bigger deal when it happens and we hear about it on the news. Longer storage and a bigger supply chain means its harder to determine the original source.
