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Did You Eat Romaine? Here Are Answers to All Your E. coli Questions

Did You Eat Romaine? Here Are Answers to All Your E. coli Questions


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We sifted through all the questions our readers had on social media, and put the most up-to-date information available into one place: Right here.

Last Friday the Centers for Disease Control and the Food and Drug Administration sent an update regarding what is now the worst outbreak of E. coli food poisoning in more than a decade.

The number of affected people has risen to 98 in 22 different states across the nation—and what's more troubling, the outbreak is sending an unusually high percentage of people to the hospital.

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Over the last few weeks, we've been updating you about the outbreak, and many of you have posted your own questions back to us. So we scoured your posts to find the most pertinent concerns, and are bringing you our best answers:

Photo courtesy of Facebook.

Doreen Paul: Where are these products coming from?

The FDA says it's still unsure of where exactly the E. coli outbreak began for a majority of the nearly 100 cases that have popped up across the nation. All we know for sure is that the romaine lettuce causing the outbreak was grown and harvested from the Yuma, Arizona region. Thankfully, the growing season in Yuma is now over, and while there may be more people who don't yet know they're sick (see below), the worst of this may be over.

Last week, reports were published linking a local Yuma operation known as Harrison Farms to the lettuce that caused eight individuals to fall ill in the Nome, Alaska region—but that leaves 90 or more cases still unsolved. According to the Los Angeles Times, health officials are still investigating dozens of other producers in the region to determine where the rest of the affected romaine heads came from.

We'll update this post should investigators release new information.

Barbara Dee Buchanan Graham: I ate salad at a popular restaurant and was sick 11 hours soon afterwards. Could I have had this?

There are a slew of symptoms that indicate you could have eaten lettuce affected by the specific variant of E. coli. The infectious virus causes diarrhea, intense stomach cramps, and heavy vomiting, and the CDC says that it takes anywhere from two to eight days for side effects of E. coli poisoning to kick in.

If you are at all concerned, you should definitely reach out to your healthcare provider to be safe—but there's a difference between E. coli sickness and more acute food poisoning, as well as other illnesses. We break down the differences between the two right here.

Karla Cintron: Is there a specific brand detected [to have] the E. coli?

As we mention above, investigators have been unable to pinpoint which producer or producers (besides one) are responsible. Unfortunately, romaine lettuce is often sold with different marketed names and packaging, and it isn't always clear on where the product came from.

The fact that many grocery stores and supermarkets will rebrand romaine lettuce purchased from third-party growers has led the FDA and CDC to ask customers to stop eating romaine lettuce altogether.

There hasn't been one brand identified in the outbreak, and unless you can clearly identify where exactly your romaine lettuce came from (i.e.: your own garden), health officials are asking you to stay away from the crunchy green until further notice.

Faith Hoffman: There was plenty of romaine (organic) and chopped bagged for sale at H-E-B (in Texas) today. Surely they've vetted it?

Following the sweeping ban from both the CDC and the FDA, many supermarkets—at both a local and national level—pulled romaine from shelves in order to avoid any shoppers becoming ill. A few weeks have passed since the initial announcement of the outbreak, and many grocery stores have taken it upon themselves to conduct internal reviews to ensure the romaine being offered in stores does not come from the Yuma region.

We've asked one of our writers to investigate the steps national supermarkets are taking to make their lettuce safe for shoppers, and we'll post more information, as well as a link to the new report, later this week.

As far as farmer's markets go, it's difficult to say. The New York Times reports that smaller farms are not subject to the same strict health regulations that larger farms have. However, if you know and trust your local farmer, and can be certain the lettuce is fresh and local (and not from Yuma) it's probably okay.

Katelyn Johnson: Anyone know if this is also in Canada?

Strangely enough, a widespread E. coli outbreak did indeed lead to more than 40 individuals getting sick in Canada earlier this year—and it was in fact due to contaminated romaine lettuce, officials concluded. While this particular outbreak linked to Arizona growers has not affected any shoppers in Canada just yet, the striking similarities of the outbreaks are pushing officials to consider a growing tide of voices calling for sweeping food safety reform.


Will Washing Romaine Lettuce Remove E. coli O157:H7?

The multistate E. coli O157:H7 HUS outbreak that is linked to romaine lettuce from the Yuma, Arizona growing region has sickened at least 121 people in 25 states. This is a serious outbreak. More than 50 people have been hospitalized. Fourteen of those people have been diagnosed with HUS, a complication of this infection that can cause kidney failure. And one person in California has died. Consumers are asking questions about this outbreak namely, how can they protect themselves and their families? One of the questions is: will washing romaine lettuce and other produce eliminate the pathogenic bacteria?

The answer is, unfortunately, no. There are several reasons for this.

First, it only takes 10 Shiga toxin-producing E. coli bacteria to make a person very sick. That tiny amount is invisible to the eye. Washing romaine lettuce will not remove all the bacteria from microscopic surface of every leaf. Experts say that washing romaine lettuce and other produce can only reduce the number of bacteria that may be present, not completely eliminate them.

Second, pathogenic bacteria such as E. coli O157:H7 can form biofilms. These bacteria tend to cluster in small clumps so they can communicate with each other and protect each other. The bacteria produce a matrix made up of proteins, polysaccharides, and nucleic acids. The matrix is very dense and protects the bacteria from cleaning agents. It also protects the bacteria from antibiotics, and even desiccation. A simple rinse with water or a cleaning solution may not penetrate that biofilm.

And finally, the deeply crenelated surface of leafy greens provides lots of places for bacteria to hide. The same is true for other types of produce, especially cantaloupe. And, if there are tiny tears, bruises, or rips in the lettuce leaf, the bacteria can actually get inside. No amount of washing any kind of produce can reach the bacteria then.

The only thing that will kill E. coli bacteria is heat the food must be heated to 160°F. There are very few recipes that call for cooked romaine lettuce. Grilling romaine lettuce halves will not increase the temperature enough to kill any bacteria that may be present.

So what can you do to protect yourself? For now, avoid romaine lettuce if you can’t positively and absolutely identify where it was grown. The Yuma, Arizona growing season is over, but romaine lettuce has a long shelf life of about 21 days. And most produce packages are not marked with the farm where the leafy green was grown. You can ask your retailer where the lettuce came from, but there is no guarantee the romaine you are about to buy is completely safe.

Remember to follow basic food safety instructions. If you have romaine lettuce in your fridge, and you aren’t 100% positive where it came from, throw it away because cross-contamination can occur between produce and the shelves and other items. Then clean your fridge with a mild bleach solution to kill bacteria. Wipe down containers with the bleach solution as well, then rinse and dry everything.

This outbreak is very dangerous. The high percentage of people who have been sick enough to be hospitalized and the high number of people with HUS demonstrate that these bacteria are very pathogenic. Don’t take a risk, especially if you or someone in your family is in a high risk group: elderly, young, pregnant, or with a chronic illness. If you or someone in your family is experiencing the symptoms of E. coli or HUS, especially if romaine lettuce has been consumed in the past 10 days, see your doctor. Those symptoms include bloody diarrhea, little urine output, pallor, lethargy, and painful abdominal cramps.

Pritzker Hageman law firm helps people sickened by contaminated food get answers, compensation and justice. Our attorneys have represented patients and families of children in personal injury and wrongful death lawsuits against food manufacturers, restaurants, retailers, schools, and others. Attorney Fred Pritzker recently won a $7.5 million judgment on behalf of a young client whose kidneys failed because he developed hemolytic uremic syndrome after an E. coli infection. If you have a question about this outbreak, ask us about it and leave a comment below. We will keep you informed as more information is released by the CDC and FDA.


Romaine lettuce warning: what you need to know

NEW YORK — Avoid all romaine lettuce, but don’t worry about your turkey.

With two food poisoning outbreaks making headlines before Thanksgiving, the messages about what’s safe to eat can be hard to keep straight. Here’s what you should know before you sit down for dinner.

WHAT LETTUCE OUTBREAK?

On Tuesday, U.S. health officials issued an unusually broad warning against all types of romaine lettuce amid an E. coli outbreak. They asked restaurants and grocers to stop selling it, people to stop eating it and everyone to throw it all out.

Thirty-two illnesses in 11 states have been linked to romaine. Canada also was affected, with 18 illnesses in Ontario and Quebec. No deaths have been reported.

WASN’T THERE ALREADY A ROMAINE OUTBREAK THIS YEAR?

Yes. The strain of E. coli in the current outbreak differs from the one linked to romaine earlier this year that sickened about 200 people and killed five. But it appears similar to the strain identified in a 2017 outbreak that happened around the same time of year.

That outbreak was linked to “leafy greens,” but a specific supplier or vegetable was never identified in the U.S.

This time, officials were able to issue an alert earlier and specifically warn against romaine because of information collected through interviews with people who got sick, said Laura Gieraltowski, of the Centers for Disease Control and Prevention.

ARE VEGETABLES CAUSING MORE FOOD POISONING?

Improved detection may be driving up the number of outbreaks tied to produce. But the way food is produced is another consideration.

Timothy Lytton, a professor of law at Georgia State University, noted that large cattle feeding lots could be a contributing factor.

WHAT DO COWS HAVE TO DO WITH E. COLI GETTING INTO LETTUCE?

Huge numbers of cows produce large quantities of animal waste. And bacteria from cattle feces can migrate into the water used to irrigate produce fields, Lytton said.

In fact, tainted irrigation water was identified as a likely source of this year’s previous E. coli outbreak linked to romaine from the Yuma, Arizona, region.

WHAT’S BEING DONE?

After the Yuma outbreak, growers in California and Arizona increased the buffer zones between animal lots and produce fields, from 400 feet to 1,200 feet. Teressa Lopez, an administrator with the Arizona Leafy Green Marketing Agreement, also noted that growers in the state started treating water that runs near animal lots. The treatment, which kills pathogens, is used on water that is going to be used on produce.

IS MORE REGULATION COMING?

The Food and Drug Administration has new rules to step up the safety of produce, but the implementation is staggered and began just recently. The agency has said inspections won’t start until next year.

Sarah Sorscher of the Center for Science in the Public Interest noted the importance of measures such as testing irrigation water. But a water-testing requirement has been contested and postponed, given the limited availability of tests that can specifically detect the harmful types of E. coli. Ultimately, that rule may not be implemented, Sorscher said.

WHY CAN’T I JUST WASH MY ROMAINE?

Washing doesn’t kill germs like the heat from cooking does. That’s why health officials are warning against all romaine.

According to a 2013 U.S. government report , leafy greens such as lettuce and spinach are the biggest source of food poisoning.

“Any product that we don’t have a cooking step is a bigger issue,” said Martin Wiedmann, a professor of food safety at Cornell.

THEN WHEN CAN I HAVE SALAD AGAIN?

It’s not clear when it will be OK to eat romaine again. Public health officials would want to be able to identify the source of the contamination or see the reported illnesses stop. Romaine has a shelf life of 21 days.

Romaine sold in the U.S. comes from different regions at different times of year. So while the romaine lettuce linked to the E. coli outbreak earlier this year was from Arizona, romaine lettuce on shelves now is mostly from California, regulators said.

Harvesting just recently began shifting back to southern California and Arizona, though most of that product has not started shipping, according to Lopez of the Arizona Leafy Green Marketing Agreement. She said suppliers were asked to withdraw products until health officials are confident the pipeline is clear of contaminated romaine.

WHAT ABOUT TURKEY?

Besides the romaine outbreak, there’s a long-running widespread salmonella outbreak linked to raw turkey in the U.S.

Raw meat and poultry is allowed to have salmonella because it’s assumed that people will cook it. That’s why regulators aren’t telling people to avoid it, they’re just reminding people to properly handle and cook their holiday birds.


There’s a Romaine Lettuce Recall in 20 States Due to Possible E. Coli Contamination

There's a major romaine lettuce recall happening right now: Tanimura & Antle, a California-based company, is voluntarily recalling its romaine lettuce heads in 20 states due to possible E. coli contamination.

The recall affects single packaged whole heads of romaine lettuce produced under the brand name Tanimura & Antle, according to a press release posted to the Food and Drug Administration (FDA) website. Only those with packaging dates of October 15 or October 16, 2020, are included. In all, the recall includes 3,396 cartons of romaine lettuce that were distributed to 20 states. (For the full list of affected products and states, check the FDA site here.)

There haven't been any illnesses reported in relation to the recall, the press release says. But the company is recalling the lettuce out of an abundance of caution after a random sampling test conducted by the Michigan Department of Agriculture and Rural Development detected E. coli on the company's lettuce. These products were sold at Walmart in clear plastic packaging with blue and white lettering.

Specifically, they detected the presence of E. coli O157:H7, which is a type of Shiga toxin-producing E. coli (STEC). Not all types of E. coli cause harmful infections, but STEC strains definitely can. The symptoms of these infections typically include stomach cramps, diarrhea (which can be bloody), and vomiting, the Centers for Disease Control and Prevention (CDC) explains. Some people will also develop a low fever.

For most otherwise healthy adults, the infection isn't serious and will go away within five to seven days without treatment, the CDC says. But for some people in more vulnerable groups, such as very young children and the elderly, an E. coli infection can become more severe. In the most severe cases, the infection can cause something called hemolytic uremic syndrome (HUS), in which the bacteria causes a form of kidney failure, SELF explained previously.

If this E. coli recall sounds familiar, it might be because there were multiple outbreaks of this particular E. coli strain in romaine lettuce back in 2018 linked to producers in California and Arizona. There was a romaine lettuce recall in both of those cases, but hundreds of people still got sick, some were hospitalized, and a few died due to the outbreaks.

Because of the shelf life for romaine lettuce and the amount of time that's already passed, the company says it's unlikely that any of the recalled products are still on store shelves. But it's worth checking your kitchen to make sure you don't have any hiding out at home.


Questions about the E. coli outbreak linked to romaine lettuce? Answers here.

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No common source of the contaminated lettuce has been identified, the CDC said, but federal health officials have begun investigating.

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Romaine lettuce at ALBA farm day (Photo: Joe Truskot/The Salinas Californian) Buy Photo

The U.S. Centers for Disease Control and Prevention issued a safety alert Tuesday for an E. coli outbreak linked to romaine lettuce after 32 people became ill in October.

No deaths have been reported, but 13 people have been hospitalized, one for a type of kidney failure associated with E. coli.

"CDC is advising that U.S. consumers not eat any romaine lettuce, and retailers and restaurants not serve or sell any, until we learn more about the outbreak," officials said. "This investigation is ongoing and the advice will be updated as more information is available."

Here are some answers to questions you may have about the recent outbreak:

Is all romaine lettuce contaminated?

CDC is advising not to eat any romaine because no grower, supplier, distributor or brand has been identified as the source of the contaminated lettuce. Officials recommend not to risk eating or buying any romaine at this time.

This applies to all types or uses of romaine, like whole heads, bags and pre-cut. If you are not sure if lettuce is romaine or if a mix has romaine, do not eat it.

What if I have some in the fridge right now?

Don't eat it. Throw it away. Make sure to wash and sanitize where it was stored.

The CDC has more information on how to properly clean your fridge.

A field of romaine in the Salinas area. (Photo: The Salinas Californian)

What are symptoms of E. coli?

The CDC says people may get sick from E. coli two to eight days after swallowing the germ. Usually, though, people develop illnesses three to four days after consuming the bacteria.

Often, symptoms include severe stomach cramps, diarrhea (often bloody) and vomiting. Those ill can also develop a fever.

A kind of kidney failure, hemolytic uremic syndrome, is rare but also possible, the CDC says. This starts about seven days after symptoms appear. Symptoms include decreased frequency of urination, feeling very tired, and losing pink color in cheeks and lower eyelids. People who develop this kind of kidney failure should be hospitalized.

It's best to check with a doctor to confirm if you have it. E. coli is usually diagnosed by stool sample.

Antibiotics are not recommended for people suspected to have E. coli until diagnostic testing can be performed.

What romaine lettuce was recalled?

Romaine has not been recalled, according to federal Food Safety information. However, the CDC is advising consumers not to eat any romaine. Retailers and restaurants should not serve or sell any until more is learned about the outbreak.

Updated information about recalls can be found here.

Is organic romaine lettuce safe to eat?

Authorities advise consumers not to eat any type of romaine.

How does lettuce get E. coli?

E. coli bacteria live in intestines of people and animals, according to the CDC. Most are harmless, but some E. coli (like Shiga toxin-producing E. coli) can cause illness outside of intestinal tracts from waste by being transmitted through contaminated water or food, as well as contact with animals or people.

What can I use instead for my salad?

There are plenty of other types of leaf lettuce you can use like red, green or butter leaf varieties that don't have advisories. Head lettuce is also fine.


Why romaine lettuce keeps getting recalled

An investigation into the leafy green’s dirty reputation.

Once a kitchen staple, the ubiquitous romaine lettuce now often conjures fear and disgust. Since 2017, contaminated romaine has sparked four major E. coli outbreaks throughout the US. Last month, the CDC reported 138 people in 25 states infected with romaine-triggered E. coli bacteria.

If you’re considering switching to kale, think again: Romaine likely isn’t any riskier than other leafy greens. Spinach and other lettuce varieties are similarly vulnerable to a harmful E. coli strain, says Purdue University food science professor Amanda J. Deering. The reason romaine has been plagued by E. Coli more than other greens has more to do with its popularity. The more romaine, the more infections.

If you feel like romaine recalls have escalated, you aren’t wrong. Food-borne-illness outbreaks from fresh produce have increased globally in recent years, Katzowitz says, likely due to increased fresh produce consumption, shifts in food production and distribution, and improved illness detection by public health officials.

Compared to other vegetables, though, our favorite salad bases are by far the most at risk for harboring dangerous bacteria. Unlike fruits and vegetables which grow higher above the ground or are protected by an outer shell or rind, leafy greens grow near the ground in open fields and are therefore susceptible to the germs from soil, water, and animal intestines, says CDC Health Communication Specialist Brian Katzowitz.

Unlike the E. coli strains that actually benefit your gut health, the O157:H7 strain is a known foodborne pathogen that commonly causes national outbreaks. When romaine comes into contact with O157, it passes infection to humans and animals. Ultimately, the strain’s origins can be difficult to track.

When an outbreak occurs, scientists view irrigation water sourced from dirty canals as a prime suspect. A November 2018 FDA report on the Yuma County, Arizona outbreak isolated the offending O157:H7 E. coli in an irrigation canal. How and when the bacterial strain entered the canal, however, is unknown.

Irrigation systems are also not the only spot in the supply chain where contamination can occur. Though processing facilities sanitize romaine before chopping it, a few infected plants can contaminate hundreds of pre-cut salad bags headed for grocery stores. This complicates FDA investigations.

“Sometimes you’re looking for a needle in a haystack,” Deering says. “It’s very hard to be sure where it’s coming from.”

Once it reaches the plate, the O157 knows no boundaries though young children and seniors are most vulnerable, the strain can infect people across ages. Symptoms of infection include diarrhea, nausea, fever, and vomiting. Those afflicted may even develop chronic kidney disease, high blood pressure, and kidney failure, according to the FDA.

Thankfully, new technology has aided the war against disease-spreading bacteria. Genome sequencing allowed researchers to trace back the O157 strains in the November 2018 romaine-based outbreak, Deering says. Plus, the 2011 Food Safety Modernization Act is considered a major win for food regulation: In an effort to thwart foodborne illnesses, it will set uniform safety standards for water, soil, and produce within most US farms by 2024. The Act’s Food Safety Plan focuses on preventive actions like identifying potential biological hazards.

During the next outbreak, check your romaine’s origin to avoid any contaminated lettuce. Though salad-eaters should tread cautiously, they needn’t abandon the infamous greens.


Questions about the romaine warning? Here are some answers

NEW YORK (AP) — Avoid all romaine lettuce, but don't worry about your turkey.

With two food poisoning outbreaks making headlines before Thanksgiving, the messages about what's safe to eat can be hard to keep straight. Here's what you should know before you sit down for dinner.

On Tuesday, U.S. health officials issued an unusually broad warning against all types of romaine lettuce amid an E. coli outbreak. They asked restaurants and grocers to stop selling it, people to stop eating it and everyone to throw it all out.

Thirty-two illnesses in 11 states have been linked to romaine. Canada also was affected, with 18 illnesses in Ontario and Quebec. No deaths have been reported.

WASN'T THERE ALREADY A ROMAINE OUTBREAK THIS YEAR?

Yes. The strain of E. coli in the current outbreak differs from the one linked to romaine earlier this year that sickened about 200 people and killed five. But it appears similar to the strain identified in a 2017 outbreak that happened around the same time of year.

That outbreak was linked to "leafy greens," but a specific supplier or vegetable was never identified in the U.S.

This time, officials were able to issue an alert earlier and specifically warn against romaine because of information collected through interviews with people who got sick, said Laura Gieraltowski, of the Centers for Disease Control and Prevention.

ARE VEGETABLES CAUSING MORE FOOD POISONING?

Improved detection may be driving up the number of outbreaks tied to produce. But the way food is produced is another consideration.

Timothy Lytton, a professor of law at Georgia State University, noted that large cattle feeding lots could be a contributing factor.

WHAT DO COWS HAVE TO DO WITH E. COLI GETTING INTO LETTUCE?

Huge numbers of cows produce large quantities of animal waste. And bacteria from cattle feces can migrate into the water used to irrigate produce fields, Lytton said.

In fact, tainted irrigation water was identified as a likely source of this year's previous E. coli outbreak linked to romaine from the Yuma, Arizona, region.

After the Yuma outbreak, growers in California and Arizona increased the buffer zones between animal lots and produce fields, from 400 feet to 1,200 feet. Teressa Lopez, an administrator with the Arizona Leafy Green Marketing Agreement, also noted that growers in the state started treating water that runs near animal lots. The treatment, which kills pathogens, is used on water that is going to be used on produce.

IS MORE REGULATION COMING?

The Food and Drug Administration has new rules to step up the safety of produce, but the implementation is staggered and began just recently. The agency has said inspections won't start until next year.

Sarah Sorscher of the Center for Science in the Public Interest noted the importance of measures such as testing irrigation water. But a water-testing requirement has been contested and postponed, given the limited availability of tests that can specifically detect the harmful types of E. coli. Ultimately, that rule may not be implemented, Sorscher said.

WHY CAN'T I JUST WASH MY ROMAINE?

Washing doesn't kill germs like the heat from cooking does. That's why health officials are warning against all romaine.

According to a 2013 U.S. government report , leafy greens such as lettuce and spinach are the biggest source of food poisoning.

"Any product that we don't have a cooking step is a bigger issue," said Martin Wiedmann, a professor of food safety at Cornell.

THEN WHEN CAN I HAVE SALAD AGAIN?

It's not clear when it will be OK to eat romaine again. Public health officials would want to be able to identify the source of the contamination or see the reported illnesses stop. Romaine has a shelf life of 21 days.

Romaine sold in the U.S. comes from different regions at different times of year. So while the romaine lettuce linked to the E. coli outbreak earlier this year was from Arizona, romaine lettuce on shelves now is mostly from California, regulators said.

Harvesting just recently began shifting back to southern California and Arizona, though most of that product has not started shipping, according to Lopez of the Arizona Leafy Green Marketing Agreement. She said suppliers were asked to withdraw products until health officials are confident the pipeline is clear of contaminated romaine.

Besides the romaine outbreak, there's a long-running widespread salmonella outbreak linked to raw turkey in the U.S.

Raw meat and poultry is allowed to have salmonella because it's assumed that people will cook it. That's why regulators aren't telling people to avoid it, they're just reminding people to properly handle and cook their holiday birds.

The Associated Press Health & Science Department receives support from the Howard Hughes Medical Institute's Department of Science Education. The AP is solely responsible for all content.

Copyright 2018 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.


FDA Advisory Alert on Romaine Lettuce and the PACA

The U.S. Food and Drug Administration (FDA) recently issued an advisory warning about an E. coli outbreak in romaine lettuce. The U.S. Department of Agriculture’s (USDA) Perishable Agricultural Commodities Act (PACA) Division provides the information below concerning the impact of the advisory on commercial sales contracts governed by the PACA.

The “allocation of the risk of loss,” determines whether the buyer or seller bears the financial loss if any damage or loss occurs to the produce before the buyer accepts it. Which party bears the loss depends on the terms of sale. For produce shipped on F.O.B. contract, the risk of loss passes from the seller to the buyer once the seller delivers the produce to the transportation carrier. Any damage or loss to the produce during transit that is not caused by the seller is borne by the buyer.

Where the contract terms of sale are “delivered”, the risk of loss is not transferred from the seller to the buyer until the produce is delivered to the contract destination. Any damage or loss to the produce during transit that is not caused by the buyer is borne by the seller.

The effect of an FDA advisory warning on contract obligations is illustrated in the following scenarios. The scenarios are based on the assumption that the advisory warns U.S. consumers not to eat the affected produce that would otherwise meet contract requirements.

Scenario 1: A seller contracts to sell produce to a buyer. Prior to shipment of the produce, the FDA issues an advisory warning that the produce is the subject of an E. coli outbreak.

In this instance the effect of the advisory warning renders the produce unmerchantable at shipment. Since the advisory was issued prior to shipment, the risk of loss remains with the seller. If the seller ships the produce, the seller may voluntarily recall the produce based upon the advisory. If the seller decides not to recall the produce, the buyer would have a claim against the seller for breach of the warranty of merchantability and could reject the produce.

Scenario 2: A seller contracts to sell produce to a buyer. After the buyer has received and accepted the produce, the FDA issues an advisory warning that the produce is the subject of an

E. coli outbreak. In this instance, the advisory warning rendered the produce unmerchantable after it was received and accepted by the buyer. Since the advisory was issued after the buyer received and accepted the produce, the risk of loss had shifted to the buyer who must pay for the produce. This result is supported by a legal decision involving Chilean grapes where the presiding officer held that a buyer must pay for the grapes although a “Stop Sale” directive had made all Chilean grapes unmerchantable. The presiding officer stated that the seller should not suffer this loss because the “Stop Sale” directive was issued two weeks after receipt and acceptance of the grapes.

Scenario 3: A seller contracts to sell produce to a buyer. While the produce is in transit from the seller to the buyer, the FDA issues an advisory warning that the produce is subject to an E. coli outbreak. In this scenario, the advisory warning renders the produce unmerchantable while in transit from the seller to the buyer. The advisory establishes a breach of the warranty of merchantability. However, resolution of this scenario depends on which party bears the risk of loss which, as discussed earlier, is dependent on the contract terms. If the terms are F.O.B. and the produce is in transit, the buyer bears the risk of loss in transit and must pay for the produce. If the contract terms are “delivered” or “delivered sale,” the seller bears the risk of loss in transit, and since the buyer in this situation has yet to receive the produce, the buyer would likely be able to reject the produce because the risk of loss rests with the seller.

These scenarios discuss the possible impact of an FDA advisory on produce contracts, but outcomes may vary depending on specific terms entered into by the parties. For more information or clarification, consult with your attorney or contact the PACA Branch at 800-495-PACA.


E. coli from beef to romaine: Can the past be the prelude?

Numerous E. coli O157:H7 outbreaks linked to Romaine lettuce have been a tragedy for both consumers and the leafy greens industry. The leafy greens industry is aggressively addressing approaches to prevent future outbreaks. This analysis is intended to share observations and recommendations for consideration that may contribute to the prevention of E. coli O157:H7 and other Shiga Toxin producing E. coli (STEC) contamination of leafy greens.

A discussion of previous efforts to reduce STEC contamination of beef, and resulting illnesses, can contribute valuable insights that relate to the detection and prevention of contamination of leafy greens. Several Food Safety Modernization Act (FSMA) rules will contribute to improving the safety of leafy greens including Standards for the Growing, Harvesting, Packing and Holding of Produce for Human Consumption (Produce Safety Rule, PSR), Current Good Manufacturing Practice and Risk-Based Preventive Controls for Human Food (Preventive Controls for Human Food), and Sanitary Transportation of Human and Animal Food.

The intent of this review is to contribute to the leafy greens related illness prevention dialog. I’m confident the industry made a concerted effort to prevent STEC related illnesses in the past. Outbreaks provide additional insights into future prevention options. The perspectives shared in this analysis, and recommendations, are solely the views and opinions of the author.

My perspective on this issue is predicated upon the following experiences:

  1. Served as the Executive Director for Regulatory Affairs for the cattle industry (1994 -2006). I was initially hired to focus on E. coli O157:H7 related issues, including meat inspection reform and establishing a science-based hazard analysis and critical control points (HACCP) approach to beef safety. During this time period I was appointed to the Secretary’s Advisory Committee for Meat and Poultry Inspection 1 .
  2. President of the U.S. food safety division (2008-2012) of a global company that developed the first E. coli O157:H7 vaccine for cattle to reduce shedding into the environment.
  3. Served as the Prevention Manager for the U.S. Food and Drug Administration’s (FDA) Coordinated Outbreak Response and Evaluation (CORE) network (2013-2017). During that time, we conducted many leafy greens related E. coli O157:H7/STEC illness cluster analysis efforts, outbreak responses, and prevention discussions.
  4. Assisted in coordinating the Produce Safety Rule oriented On-Farm Readiness Review (OFRR) training programs under the leadership of the National Association of State Departments of Agriculture (NASDA), the FDA, and produce oriented professionals from several State Cooperative Extension Services 2 .
  5. Currently serving as a food safety consultant, focused on prevention efforts linked to achieving compliance with FDA Preventive Controls for Human and Animal Food, Foreign Supplier Verification, and the Produce Safety Rule. In addition, I have served as an expert on several foodborne illness litigation cases.

Based on these experiences, and analysis, the information and opinions included here are intended to stimulate a discussion regarding recommendations for consideration by leafy greens growers, processors, and the food service sectors.

A farm to table risk reduction strategy should be considered as critically important to the prevention of E. coli O157:H7/STEC illnesses linked to leafy greens in general and Romaine in particular.

E. coli O157:H7 outbreaks, prevention efforts associated with beef

The history of beef E. coli O157:H7 prevention efforts provides insights into facets that should be considered when developing plans to address E. coli O157:H7 illness prevention related to produce.

From November 15, 1992 to February 28, 1993 more than 500 laboratory-confirmed infections caused by E. coli O157:H7 linked to ground beef were identified. By the time the outbreak was over, more than 700 people had been infected.

This incident would forever be a life changing event for many, and the force behind a policy, legislative, and regulatory sea-change in meat inspection and prevention of foodborne illnesses.

The E. coli O157:H7 outbreak resulted in the most significant change in meat inspection legislation since 1906 3 . It was the catalyst for the establishment of a government and industry-wide focus on a Hazard Analysis and Critical Control Points (HACCP) approach to beef safety.

The risk of E. coli O157:H7, and resulting human illnesses associated with beef, has decreased dramatically since 1993. In 1997 the Centers for Disease Control and Prevention (CDC) set a goal of less than 2.1 cases/100,000 by 2010. By 2005 the incidence rate had dropped by 42 percent to 0.9 cases/100,000 4 . Since 2005 incidence rates have climbed slightly, primarily due to increased leafy greens related outbreaks and more laboratory testing of patients. Rangel et al. 2005 4 reported that 41 percent of outbreaks were linked to beef and 21 percent to leafy vegetables. In 2018, CDC reported 5 the incidence rate for E. coli O157:H7 was 0.72/100,000 and non-O157 at 0.97/100,000. Recent outbreaks associated with beef products indicate the risks continue to pose a prevention challenge.

The reasons for the decline in risk associated with beef products are multifaceted and include:

  1. USDA declaring E. coli O157:H7 an adulterant in ground beef.
  2. USDA requirements that industry establish a HACCP-based approach to reducing contamination.
  3. Industry establishment of multiple hurdles that each reduce the risk of
    E. coli O157:H7 contamination such as: antimicrobial rinses, hot water washing and steam applications.
  4. USDA development of more highly sensitive culture methods for detecting E. coli O157:H7.
  5. Changes in the Food and Drug Administration’s Model Food Code that recommend the food service sector cook ground beef to 155° F. Consumers were encouraged to cook ground beef to 160° F.
  6. Industry driven transportation and storage requirements ensuring that beef trim in transit to processors remain at or below 40° F to reduce the potential for growth of pathogens.
  7. Industry requirements for a test and hold program for ground beef and associated certificates of analysis (COA). Some industry sectors routinely verify the COA data.
  8. Educational initiatives for food service and consumers to help ensure proper cooking.
  9. Continued research and development of improved sampling techniques such those published by Wheeler and Arthur, 2018 6 .

Considerations for a farm-to-table approach to

Reducing the Risk of E. coli O157:H7/STEC Associated with Leafy Greens
The leafy greens sector has invested a great deal of resources in the development and implementation of initiatives such as the California Leafy Greens Marketing Agreement (LGMA) and the Arizona LGMA. I believe these efforts have utilized the most up-to-date, and science-based information. However, information gleaned from recent outbreaks has resulted in additional efforts to enhance these initiatives.

In addition, produce marketing associations, Cooperative Extension Service professionals, and private sector consultants have been contributing to other efforts to reduce the risk of pathogens associated with leafy greens.

There are also many audit schemes ranging from the USDA GAPs to third party audits that are all intended to contribute to the production of safe leafy greens, and other produce.

With the passage of the Food Safety Modernization Act, and development of the Produce Safety Rule (PSR), States and the FDA are beginning to inspect leafy greens producers to ensure compliance with the PSR.

The National Association of State Departments of Agriculture (NASDA) has been coordinating, in concert with the FDA, the On-Farm Readiness Review (OFRR) program 2 . This effort brings a coordinated, standardized approach to training of State regulatory, Cooperative Extension and produce growers. This initiative’s focus contributes to “Educating Before You Regulate” to help ensure compliance with the PSR.

As States and the FDA begin PSR compliance inspections they will operate under a mindset of “Educate Before and While You Regulate”. This approach will increase the likelihood that produce growers learn about PSR compliance requirements while they are being inspected. This is intended to contribute to both higher levels of producer compliance as well as reductions in specific food safety risks.

With all these activities and initiatives underway a natural question is why do we continue to have so many E. coli O157:H7/STEC outbreaks associated with leafy greens in general, and Romaine in particular?

Potential weak links in farm-to-table produce safety

1. Analysis of Individual Farm Production Risks
I have observed that many food production firms, in general, often look to others to set their food safety benchmarks. These benchmarks might be information found in the various FDA hazard guides, or in the case of produce, LGMA oriented information, USDA GAP, and third-party audit scheme checklists.

It is important to keep in mind, based upon analysis of numerous outbreaks, that adhering to these “hazards guides” and audit schemes alone may not fully protect growers and processors from being accused of causing a problem and potentially ending up in court.

These “hazard guides” should only be viewed as a starting point to develop an individual firm or farm hazard analysis and food safety plan. A comprehensive farm and processor specific hazard analysis are essential to help ensure the production of safe food.

2. Developing and implementing a farm specific produce safety plan is a significant investment.
Farm profitability can be a challenge and effective investments in food safety might be compromised as a result of compliance costs associated with the PSR and simultaneous third-party audit schemes. If these costs are not providing a return on investment in terms of real reductions in food safety risk, they may indirectly be contributing to foodborne illness outbreaks. It is important investments in food safety practices and technology are highly correlated with achieving food safety objectives.

For example, in 2018, the Economic Research Services 7 estimated the PSR compliance costs would range from just over $1,700 for small farms to over $37,000 for very large farms. These costs appear reasonable although the PSR compliance requirements must be viewed as a foundation level of food safety risk reduction approaches.

In 2017, The Economic Research Service 8 surveyed produce growers to determine the costs related to food safety under their food safety plans, including costs of third-party or other audit schemes. Growers reported on costs for food safety staff, foremen food safety time, audits, lost product due to animal intrusion, and water testing.

The survey found that between 27 and 38 percent of all food safety related costs were linked to third-party audit schemes. These costs ranged from a low of $27,150 to a high of $305,403 per farm annually.

The survey also found total food safety plan costs on farms (food safety staff, foremen food safety time, audits, lost product due to animal intrusion, and water testing) ranged from $120,501 to $1,297,063. If you were paying that kind of money and still ended up with a food safety problem, it’s time to consider other options.

Recommendation
The produce industry and its customers should consider the cost and benefits of multiple third-party audit schemes. These schemes understandably go well beyond the requirements of the FDA PSR, some of the required processes may represent potentially costly expenditures as reported in the ERS survey. The concern is if all these costs, food safety audits and related expenses are not focused on a farm’s real produce safety risks, the processor, retailer, and public remain at risk.

Specific, individualized farm/firm hazard analysis, and resulting food safety plans should provide the framework that is evaluated against risk-based food safety benchmarks, not checklist-based auditing schemes. The expense of multiple, generic, far-ranging audit schemes may be contributing to a lack of resources focused on the real food safety risks. Some producers may believe if they are complying with the PSR, audit schemes, or marketing agreement requirements their produce will be safe. History is telling us something very different.

Sources of E. coli O157:H7/STEC and potential transfer routes to produce

Numerous studies have documented that the primary environmental reservoir of E. coli O157/STEC is cattle. Cattle shed E. coli O157:H7/STEC into the environment at varying rates from individual animals and times of the year.

Reducing the risks presented by cattle operations have focused on establishing setbacks from cattle (beef and dairy) operations and water testing. As outbreaks continue, these setbacks and water analysis methods are under review.

Proximity to cattle operations must be viewed as an E. coli O157:H7/STEC hazard. Routes of pathogen movement to produce should be analyzed. If no route of transfer exists, there is no hazard reasonably likely to occur.

Cattle operations are under numerous regulatory requirements, not the least of which is that the EPA does not allow any discharge of contaminated water into the surface waters of the United States. Thus, water may not represent the most likely route of transfer of the pathogen to produce. The EPA does not regulate fugitive dust from cattle operations, although it has been evaluated 9 .

The FDA Yuma environmental assessment 10 (FDA EA) relating to E. coli O157:H7 contamination of Romaine found the three illness-causing strains in the Wellton canal. One was to the west of a feedlot, one adjacent, and another to the northeast. The stretch of the Wellton canal where the positive samples were taken was approximately 3.5 miles in length.

To what extent these positive samples indicate water was the source of the hazard, and water use the route of transfer or exposure, should be carefully evaluated. Is Wellton canal water the most likely route of transfer of the hazard?

Water as a risk factor in a hazard analysis
The FDA EA did not mention the flow rate of water in the Wellton canal at the time of harvest associated with the outbreak, nor during their sampling in June 2018. An analysis of the flow rate in the Wellton canal and potential location of farms that may be implicated in shipping of contaminated produce, needs to be considered.

Currently we do not know where farms suspected of producing contaminated Romaine are relative to being “up-stream or down-stream” from the feedlot mentioned in the FDA EA and where the positive E. coli O157:H7 Wellton canal water samples were taken.

From a hazard analysis perspective, consideration of the rate of water flow passing Yuma and ultimately the cattle feedlot, from the west to the east, in February and March was as follows 11 :

Water Flow Unit February 2018 March 2018
Acre Feet/Day Average 830.7 1,139.6
Cubic Feet/Second Average 419 575
Gallons Per Day 270,667,908 371,339,800
Gallons Per Second 3,134 4,298

The actual water flow rate passing the feedlot would be lower than these rates due to flow into laterals in the system. However, flow rates passing the feedlot would still be significant. Given these water flow rates it is difficult to imagine how a contaminant entering the canal, near a feedlot, would remain in proximity to the point of initial contamination. In addition, the water flow rates in the canal, raise the issue of how would you take a representative sample of water that is flowing at a rate of 3,000 gallons per second?

Laboratory Methods
Another issue worth discussing is that there isn’t a perfect correlation between generic

E. coli measurements and E. coli O157:H7. This issue is discussed in several publications including by Cooley et al. 2007 12 relating to the 2006 contaminated Spinach event.

Application of water to the harvestable portion of a crop is an issue. Consequently, water tests associated in “real time” with the water being applied are important.

If the hazard being monitored is E. coli O157:H7/STEC, laboratory methods should be used that have the proper sensitivity and specificity to detect the pathogen. In

addition, sampling methods need to represent a statistically valid number of samples.

The FDA EA doesn’t include information regarding methods the Centers for Disease Control and Prevention (CDC) used to identify the three illness-causing E. coli O157:H7 “strains” from Wellton canal water samples. That information would he helpful in an analysis of testing methods.

One of the most significant steps USDA took to deal with the threat of E. coli O157:H7 in beef was the development of very sensitive tests used for regulatory purposes. The current USDA E. coli STEC test description can be found in the February 2019 updated USDA Laboratory Handbook, MLG 5C.00 13 method. It employs “enrichment in a selective broth medium, application of a rapid screening test, immunomagnetic separation (IMS) in paramagnetic columns, and plating on a highly selective medium, modified Rainbow Agar (mRBA)”.

Recommendation
If produce growers believe there is a risk of contamination of produce due to E. coli O157:H7/STEC contamination of water applied to the harvestable portion of the crop, careful consideration of the laboratory methods used to test water should be considered. This includes the number of samples that would be necessary to provide a statistically valid sample. The time period for testing should be aligned with application of the water to the harvestable portion of the crop. Testing for generic E. coli strains may not provide information necessary to make a truly informed decision regarding water source and use patterns relating to a potential “hazard reasonably likely to occur”.

Weather events as a factor in hazard analysis
During my tenure with FDA CORE it became clear that weather events played a significant role by contributing to the movement of pathogens (route) from their source (hazard) on to or into food. A hazard coupled with a route of movement equates to a hazard reasonably likely to occur.

For example, it is suspected that weather events in Tuna fisheries may contribute to sewage entering the ocean and resulting contamination of Tuna with Salmonella and other pathogens. The exact route of contamination is difficult to determine but weather events provided a way for pathogens in human waste to enter the ocean during a storm event. It could be the fish themselves became contaminated internally or externally due to being in contaminated water. The 2015 hurricane season in the Pacific was the second most active on record 14 . Several storm events impacted the Baja Peninsula. This may have led to Salmonella Poona contamination of cucumbers grown on the peninsula.

Romaine growers in the Yuma Arizona area reportedly told the FDA EA team 10 a significant weather event occurred in February 2018. It included high winds and below freezing temperatures. It is important to note that with storm events, the wind can shift 360 degrees as a low-pressure weather event occurs. In the Yuma area, could the weather event winds have shifted to the southeast, south, or southwest moving dust from a feedlot over fields, depositing it on produce, resulting in microbiological contamination?

This naturally raises the following questions for consideration in a hazard analysis:

  1. Is there a source of dust associated with cattle in the vicinity of produce fields (a hazard)?
  2. How much dust do cattle produce?
  3. What is the size of the dust particles?
  4. Can dust carry pathogens?
  5. How far can dust from cattle operations travel during a wind event (route of hazard movement)?

Some of the answers to these and other questions can be found in published literature and information from the Environmental Protection Agency (EPA).

For example, in 2015 the EPA published a summary document titled “Fugitive Dust from Beef Cattle Operations 9 . In this document, the EPA estimated total dust emissions from cattle feedlot operations of 17 tons/1,000 head/year. The smaller particles of concern are classified as PM2.5 and PM10. It is estimated that 15% of the total emissions would be PM2.5 – PM10. The PM designation relates to the size in microns. This equates to an estimate of 2.5 tons of PM2.5 -PM10 per 1,000 head/year.

A study conducted by McEachran et al. in 2015 15 used an estimate of 28.5 grams of PM10/head/day from feedlots, which equates to 62.8 lbs./1000 head/day or 11.5 tons/year/1000 head. This would equate to 6,278 lbs. of PM10 and smaller particles per day/100,000 head of feedlot cattle.

In a study by Hiranuma et al. (2011) 16 found measurable amounts of PM material traveled as far as 2.2 miles from a feedlot location. This study did not establish the maximum distance measurable PM10 or smaller particles can travel.

The question of how far PM25 and smaller particles of dust can travel is perhaps best illustrated by the movement of PM type dust from the Sahara. PM25 and smaller dust particles from the Sahara routinely travel across an expanse of 3,000 miles of the Atlantic Ocean and are deposited on the Amazon Basin. Swap et al. 1992 17 estimated that during individual storm events as much as 480,000 tons of the PM material originating from the Sahara are deposited on the Amazon Basin.

Questions have been raised regarding if microbes survive transport on dust due to desiccation or UV radiation. Dust has been documented to be capable of carrying viable E. coli O157:H7. Berry et al. 2015 18 studied the movement of dust from a feedlot and reported that over a two-year time period, E. coli O157:H7 and total E. coli were recovered at all produce plot distances, up to 590 feet. This study did not identify the upper limit of dust movement harboring viable pathogens. They noted the risk of movement is increased when pen surfaces are dry. Nighttime movement of contaminated dust would reduce the potential for decontamination due to UV light prior to deposition.

The FDA conducted an EA after a 2010 outbreak associated with E. coli O145 in shredded lettuce grown in the Yuma area 19 . Carter et al. 2016 20 reported on the studies of E. coli O145 found in a major produce region in California. Some of the strains have greater virulence than others. A review of the prevalence of STEC in dairy cattle by Hussein and Sakuma 2005 20 clearly indicate the hazards presented by STEC are not limited to beef cattle.

Recommendation
From a hazard analysis perspective, a beef feedlot or dairy operations in proximity to produce fields, represents an STEC hazard. Weather and associated wind events can carry dust harboring pathogens significant distances. From a hazards analysis perspective there is a source and a route of transmission (wind) resulting in STEC’s originating from a feedlot or dairy as a hazard reasonably likely to occur. Consequently, steps must be taken to understand the risk and control this hazard, including weather event related produce safety actions.

Microbial testing considerations as a risk identification s trategy

Let’s assume you have determined what hazards are reasonably likely to occur during the production, processing, distribution or use of a food item at retail. From this analysis you have developed a food safety plan including measures to reduce the risks presented by the hazards. How you monitor the risks reduction steps is important.

Microbial testing has always been a sensitive topic. I have been in many meetings where individuals have discouraged firms from testing. The issue has been concerns regarding what such testing might find or what testing implies about risks. These concerns increased with the establishment of the Reportable Food Registry 22 requirements. I’m not an attorney but it seems logical that some microbial testing and associated efforts to verify you are at least attempting to reduce risk would be viewed as industry expected due diligence.

Most firms purchasing food items, either raw or finished ingredients, require a Certificate of Analysis (COA) including several testing requirements. These requirements often include microbiological, mycotoxins, heavy metals and pesticide residue tests. These tests may be required as a function of Hazard Analysis and Risk Based Preventive Controls (HARPC). These plans usually include verification of the COA information.

On September 27, 2007 Congress approved the Food and Drug Administration Amendments Act of 2007 22 . Section 1005 of that legislation required FDA to establish a “Reportable Food Registry”. The RFR provides an electronic portal for industry to report when there is reasonable probability that an article of food will cause serious adverse health consequences. The RFR is intended to help the FDA better protect the public health by tracking patterns and targeting inspections.

The RFR, in general, makes sense, however in the real-world, if a firm were to report to the RFR a low level of Listeria monocytogenes (LM) in say ice cream, what might FDA do? Recent history illustrates they would determine any level of LM in a ready to eat product represents a “reasonable probability that an article of food will cause serious adverse health consequences”.

FDA has essentially set a zero tolerance for LM in ready to eat foods, even though the Codex standard remains at 100 CFU/gram as a safe level of the pathogen, arguably, only for not at-risk populations. An LM outbreak associated with ice cream caused the death of at least 5 patients in 2016. Analysis of ice cream linked to the outbreak found low levels of LM in samples. The evaluation showed 92% of samples

were contaminated at less than 20 MPN/g 23 . Prior to this outbreak, ice cream was not viewed as a high risk for LM contamination since it would not support growth when stored at cold temperatures. Each outbreak provides an opportunity to better understand food safety hazards. The FDA published updated LM guidance for industry shortly after this event.

The RFR created a situation where testing a ready to eat food item and finding any level of a pathogen could present a “reasonable probability that an article of food will cause serious adverse health consequences.” This reality added additional resistance to conducting culture-based microbiological analysis of food items. The uncertainty regarding how FDA would interpret the information considering the “reasonable probability that an article of food will cause serious adverse health consequences” added to these challenges.

Consequently, the RFR provided an incentive for the development of microbial testing systems that were based on DNA/PCR analytical platforms. There are several companies offering DNA/PCR based testing platforms. In general, these platforms provide a report indicating the relative likelihood a food item has a level of a pathogen presenting a “reasonable probability that an article of food will cause serious adverse health consequences.”

These tests technically reduce the pressure to report findings to the RFR because they are not actually detecting viable cells of a pathogen, rather only their DNA. The challenge for firms is to fully understand the DNA/PCR technology and what the resulting numbers mean in terms of risk to public health.

From my experience, most leafy greens produced in the U.S. are subject to COA requirements. The most common analytical methods used to meet the COA requirements are DNA/PCR based tests.

In the case of E. coli O157:H7, DNA/PCR tests are likely not as sensitive as the testing methods used, for example by USDA, that employ “enrichment in a selective broth medium, application of a rapid screening test, immunomagnetic separation (IMS) in paramagnetic columns, and plating on a highly selective medium, modified Rainbow Agar (mRBA) 13 ”. Thus, it is likely these methods will not provide a true representation of risk posed by a sample of leafy greens.

Recommendation
Microbiological testing of leafy greens and other food items, in the face of an E. coli O157:H7/STEC hazard determined to be reasonably likely to occur, must use methods sensitive enough to detect the pathogen. There is virtually no safe level of STEC’s in ready to eat foods.

Impact of temperature, time on pathogen growth in processed leafy greens

As foodborne illness clusters are identified, often the first cases provide clues to the geographic origin of the pathogen. For instance, in the Jensen Farms of Colorado Cantaloupe LM outbreak, the first cases identified were in Colorado. Eventually cases were identified across the United States.

When the Romaine outbreak of 2018 occurred, the first cases were in the Northeast. This led to some preliminary concern the Romaine may originate in a greenhouse system in that region. Of course, the outbreak ultimately resulted in cases in 36 States. This illness outbreak pattern in the Northeast was very similar to the 2010 E. coli O145 outbreak linked to chopped leafy greens originating from the Yuma area, as reported by the CDC 21 . In the 2018 outbreak it was quickly determined the source of the outbreak was Romaine from the Yuma Arizona area.

This led to asking the question, could processing of Romaine and subsequent transportation and storage from distribution centers to retail locations be contributing to risk?

It is a common practice to monitor the temperature of leafy greens from harvest through transportation to processing. However, it is less clear what temperatures processed/chopped leafy greens experience over their remaining shelf life, up to14 days after initial harvesting. The FDA is in the process of enforcing the final rule on Sanitary Transportation of Human and Animal Food 24 . This will generate incentives to control the temperature of leafy greens during transport. Risks may remain if temperatures at retail or at home are not controlled.

A study by Luo et al. 26 2010, demonstrated that E. coli O157:H7 inoculated, chopped Romaine and Iceberg lettuce, stored in N2 flushed bags, showed no additional growth at 5° C, when sampled periodically until their “Best If Used By” dates. Conversely, the chopped Romaine and Iceberg lettuce stored at 12° C were found to have more than a 2 log CFU/g increase of the pathogen within 3 days. These research results are consistent with work published by Zeng et al. 2014 27 .

Coleman et al. 2013 28 studied handling practices of fresh leafy greens in restaurants, including product receiving requirements. They reported 49 percent of the shipments were received at temperatures over 41° F, 24.3 percent were received at between 42°- 45° F, 18.9 percent were received at 46°-54° F, and 8.1 percent were received at greater than 55° F.

This raises the question, could a low level of E. coli O157:H7/STEC, one low enough to not cause illness itself, multiply post processing to a level that could cause significant illnesses? The answer is yes, contamination of ready to eat foods with STEC or other pathogens can increase over time if the products are exposed to temperatures and time intervals that support growth. Risks can increase from the farm to the table as even a very low number of pathogens can increase by several logs over time, increasing the risk to public health.

Recommendation
The risk of illness caused by E. coli O157 and other STEC can increase from the farm to the table under some circumstances. Even if sophisticated testing indicates an absence of these pathogens on leafy greens at harvest, temperature of the product needs to be reduced as quickly as possible and maintained at a temperature of at least 40° F or less throughout its shelf life to control risk.

Summary: recommendations for leafy greens, produce sectors to reduce risk of E. coli O157/STEC contamination and human illness
  1. The concept of a multiple hurdle approach to reducing the food safety risk of leafy greens is not a new idea. Recently, Mogren et al. 2018 29 published a review of potential hurdles to microbial contamination and potential reductions of risk associated with leafy greens. Analysis of recent outbreaks has contributed to identifying the additional risk factors in the current hazard analysis for leafy greens production, processing and distribution systems.Farms, processors, distributors, and the retailers need to conduct a hazard analysis and fully understand that achieving food safety goals requires steps along the entire path from the farm to the table. Although not required by the PSR, it is highly recommended individualized food safety plans should be the result of this effort.
  2. Development of individualized farm/firm specific hazard analysis-based produce safety plans is vitally important. Reliance on FDA guidance, audit schemes or marketing agreement requirements alone, has not, and will not comprehensibly ensure the safety of produce.
  3. It is critically important produce growers understand the E. coli O157/STEC hazards presented by beef and dairy cattle operations, particularly in dry environments. Evidence suggests wind blown dust can carry pathogen laden particles, in the PM10 range for miles, depositing them on crops. The upper limit of their potential movement, and viability of pathogens being transported, has not been established. Risk of these particles moving should be based upon published atmospheric science research relating to the movement of PM10. This risk has not been comprehensively addressed in existing production guidance or other peer reviewed publications.
  4. Weather events and post event response plans need to be included and defined within individual farms/firms hazard identification and control plans.
  5. Microbial testing of water that contacts the harvestable portion of produce must be more robust if the risk of E. coli O157:H7/STEC is identified. Water testing should occur prior to application to the harvestable portion of the crop. Generic E. coli testing is not highly correlated with the presence E. coli O157:H7/STEC. Statistically valid sampling of water sources should account for source flow rates.
  6. If E. coli O157:H7/STEC is considered a hazard reasonably likely to occur, microbiological testing of produce contributing to a COA, including as a field release criterion, must use highly specific and sensitive methods. Methods such as the FSIS MLG 5C.00 9 should be considered when evaluating appropriate methods.
  7. Temperature of produce, especially during and post processing, is a factor in controlling the risk of E. coli O157:H7/STEC. Virtually undetectable levels of E. coli O157:H7/STEC on chopped produce can rapidly multiply to infectious levels when temperatures rise above 40° F where rapid growth is supported. From the farm to the table, the temperature of produce, especially chopped produce, must remain at or below 40° F. Firms processing produce are subject to the temperature control provisions of the Preventive Controls for Human Food rule. The FDA Sanitary Transport rule requires temperature controls as well.
  1. When receiving produce, it is important that storage and shipping temperatures are verified to have been at or below 40° F. Shipments should be rejected if they have been subject to temperature abuse.
References

National Advisory Committee on Meat and Poultry Inspection. 1999. Federal Register 55225 Vol. 64, No. 196. October 12, 1999. https://www.fsis.usda.gov/wps/wcm/connect/4bac9a96-39bb-43a1-870a-500a8850c1b7/99-044N_226.pdf?MOD=AJPERES

  1. On-Farm Readiness Reviews https://www.nasda.org/foundation/food-safety-cooperative-agreements/on-farm-readiness-review
  1. FSIS Timeline of Events Related to E. coli O157:H7. 2005. https://www.fsis.usda.gov/wps/portal/fsis/topics/regulatory-compliance/haccp/updates-and-memos/timeline-of-events-related-to-e-coli-o157h7/e-coli-timeline
  2. Rangel, J.M., Sparling, P.H., Crowe, C., Griffen, P.M. Epidemiology of Escherichia coli O157:H7 Outbreaks, United States, 1982–2002. https://www.researchgate.net/publication/7908247_Epidemiology_of_Escherichia_coli_O157H7_Outbreaks_United_States_1982-2002
  3. National Enteric Disease Surveillance: Shiga Toxin-producing Escherichia coli (STEC) Annual Report, 2016. Data current as of April 16, 2018. https://www.cdc.gov/ecoli/surv2016/index.html
  4. Wheeler, T and Arthur, T. 2018. Novel Continuous and Manual Sampling Methods for Beef Trim. Journal of Food Protection, Vol. 81, No. 10:1605–1613. 2018
  5. Bovay, J., Peyton Ferrier, P., Chen Zhen, C., 2018. Estimated Costs for Fruit and Vegetable Producers to Comply with the Food Safety Modernization Act’s Produce Rule. USDA Economics Research Service. Economic. Information Bulletin Number 195. https://www.ers.usda.gov/publications/pub-details/?pubid=89748
  1. Calvin, L., Helen Jensen, H., Karen Klonsky, K., Cook, R. 2017. Food Safety Practices and Costs Under the California Leafy Greens Marketing Agreement. Economic Research Service. Economic Information Bulletin Number 173. https://www.ers.usda.gov/publications/pub-details/?pubid=83770
  2. EPA: Fugitive Dust from Beef Cattle: https://www.epa.gov/sites/production/files/2015-08/documents/feedlots.pdf
  1. FDA Yuma Environmental Assessment 2018.
    https://www.fda.gov/food/outbreaks-foodborne-illness/environmental-assessment-factors-potentially-contributing-contamination-romaine-lettuce-implicated
  1. Wellton Canal Water Flow Rate Data, February, March 2018. Pages 4-5. https://az.water.usgs.gov/projects/LowerColoradoRiverReports/reports/2018/2018_02.pdf
    https://az.water.usgs.gov/projects/LowerColoradoRiverReports/reports/2018/2018_03.pdf
  1. Cooley, M., Carychao, D., Crawford-Miksza, L., Jay MT, Meyers, C., Rose, C., Keys, C., Farrer, J., Mandrel, R.E., 2007. Incidence and Tracking of Escherichia coli O157:H7 in a Major Produce Production Region in California. PLOS ONE November 2007 Issue 11, e.1159. https://www.ncbi.nlm.nih.gov/pubmed/18174909
  2. USDA Laboratory Handbook MLG 5C.00 https://www.fsis.usda.gov/wps/wcm/connect/7ffc02b5-3d33-4a79-b50c-81f208893204/MLG-5B.pdf?MOD=AJPERES
  1. National Hurricane Center Annual Summary 2015 Eastern North Pacific Hurricane Season. https://www.nhc.noaa.gov/data/tcr/summary_epac_2015.pdf
  2. McEachran, A.D., Blackwell, B.R., Hanson, J.D., Wooten, K.J., Mayer, G.D., Cox, S.B., Smith, P.N. 2015. Antibiotics, Bacteria and Antibiotic Resistance Genes: Aerial Transport from Cattle Feed Yards vis Particulate Matter. Environmental Health Perspectives Volume 123: Number 4: 337-343. https://dx.doi.org/10.1289/ehp.1408555
  3. Hiranuma, N, Brooks, S.D. Gramann, J., Auvermann, B.W. 2011. High Concentrations of Coarse Particles Emitted from a Cattle Feeding Operation. Atmos. Chem. Phys., 11: 8809–8823. https://www.atmos-chem-phys.net/11/8809/2011/ doi:10.5194/acp-11-8809-2011. https://www.atmos-chem-phys.net/11/8809/2011/
  4. Swap, R., Garstang, M., Greco, S., Talbot R., Kallberg, P., 1992. Saharan Dust in the Amazon Basin. TellusB: Chemical and Physical Meteorology, Volume 44:2:133-149. https://www.tandfonline.com/doi/abs/10.3402/tellusb.v44i2.15434
  5. Berry, E. D. Berry, Wells, J.E., Bono, J.L., Woodbury, B.L., Kalchayanand, N., Norman, K.N., Suslow, T.V., López-Velasco, G., Millner, P.D. 2015. Effect of Proximity to a Cattle Feedlot on Escherichia coli O157:H7 Contamination of Leafy Greens and Evaluation of the Potential for Airborne Transmission. Applied and Environmental Microbiology February 2015. Volume: 81, Number: 3:1101-1110. https://www.ncbi.nlm.nih.gov/pubmed/25452286
  6. Environmental Assessment Report FDA Foods Program Non-O157 Shiga Toxin-Producing E. coli (STEC) Environmental Assessment. https://wayback.archive-it.org/7993/20171114155100/https://www.fda.gov/Food/RecallsOutbreaksEmergencies/Outbreaks/ucm235477.htm
  1. Carter, M.Q., Quinones, B., He, X., Zhong, W., Louie, J.W., Lee, B.G., Yambao, Y.C. Mandrell, R.E., Cooley, M.B. 2016. An Environmental Shiga Toxin-Producing Escherichia coli O145 Clonal Population Exhibits High Level Phenotypic Variation That Includes Virulence Traits. Applied and Environmental Microbiology, February 2016. Volume 82. Number 4:1090-1101. https://aem.asm.org/content/82/4/1090
  2. Hussein, H.S. and Sakuma, T. 2005. Invited Review: Prevalence of Shiga Toxin-Producing Escherichia coli in Dairy Cattle and Their Products. J. Dairy Sci. Volume 88:450-465. https://www.journalofdairyscience.org/article/S0022-0302(05)72706-5/pdf
  3. Food and Drug Administration Amendments Act of 2007.
    https://www.govinfo.gov/content/pkg/PLAW-110publ85/pdf/PLAW-110publ85.pdf
  1. Chen,Y., Burall, L.S., Macarisin, D., Pouillot, R. Strain, E., J. De Jesus, A.J., Laasria, A., Wang, A., Ali, L., Aptatavarthy, A., Zhang, G., Hu, L., Day, J., Kang, J., Sahu, S., Srinivasan, D., Klontz, K., Parish, M., Evans,P.S., Brown, E.W., Hammack,T.S., Zink, D.L., DATTA, A.R., 2016. Prevalence and Level of Listeria monocytogenes in Ice Cream Linked to a Listeriosis Outbreak in the United States. Journal of Food Protection, Vol. 79, No. 11, 2016, Pages 1828–1832. https://jfoodprotection.org/doi/pdf/10.4315/0362-028X.JFP-16-208
  2. Multistate Outbreak of Human E. coli O145 Infections Linked to Shredded Romaine Lettuce from a Single Processing Facility (FINAL UPDATE) https://www.cdc.gov/ecoli/2010/shredded-romaine-5-21-10.html
  3. FDA Final Rule on Sanitary Transport of Human and Animal Food. 2016.
    https://www.fda.gov/food/food-safety-modernization-act-fsma/fsma-final-rule-sanitary-transportation-human-and-animal-food
    https://www.fda.gov/regulatory-information/search-fda-guidance-documents/guidance-industry-sanitary-transportation-human-and-animal-food-what-you-need-know-about-fda
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About the author: Gary M. Weber, PhD, is with G.M. Weber Consulting. Weber has more than 30 years experience working on food safety and agricultural issues for the USDA, FDA, the private sector, and trade associations. He has extensive experience working with the media and has testified under oath numerous times before Congress. He serves as a consultant and expert witness. He served over four years as Prevention Manager for the FDA Coordinated Outbreak Response and Evaluation Network (CORE) where he handled more than 100 significant food-borne outbreaks.

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Answers to questions about romaine lettuce warning

Romaine Lettuce still sits on the shelves as a shopper walks through the produce area of an Albertsons market Tuesday, Nov. 20, 2018, in Simi Valley, Calif. Health officials in the U.S. and Canada told people Tuesday to stop eating romaine lettuce because of a new E. coli outbreak. (Photo: Mark J. Terrill / AP)

New York – Avoid all romaine lettuce, but don’t worry about your turkey.

With two food poisoning outbreaks making headlines before Thanksgiving, the messages about what’s safe to eat can be hard to keep straight. Here’s what you should know before you sit down for dinner.

What lettuce outbreak?

On Tuesday, U.S. health officials issued an unusually broad warning against all types of romaine lettuce amid an E. coli outbreak. They asked restaurants and grocers to stop selling it, people to stop eating it and everyone to throw it all out.

Thirty-two illnesses in 11 states have been linked to romaine. Canada also was affected, with 18 illnesses in Ontario and Quebec. No deaths have been reported.

Wasn’t there already a romaine outbreak this year?

Yes. The strain of E. coli in the current outbreak differs from the one linked to romaine earlier this year that sickened about 200 people and killed five. But it appears similar to the strain identified in a 2017 outbreak that happened around the same time of year.

That outbreak was linked to “leafy greens,” but a specific supplier or vegetable was never identified in the U.S.

This time, officials were able to issue an alert earlier and specifically warn against romaine because of information collected through interviews with people who got sick, said Laura Gieraltowski, of the Centers for Disease Control and Prevention.

Are vegetables causing more food poisoning?

Improved detection may be driving up the number of outbreaks tied to produce. But the way food is produced is another consideration.

Timothy Lytton, a professor of law at Georgia State University, noted that large cattle feeding lots could be a contributing factor.

What do cows have to do with E. coli getting into lettuce?

Huge numbers of cows produce large quantities of animal waste. And bacteria from cattle feces can migrate into the water used to irrigate produce fields, Lytton said.

In fact, tainted irrigation water was identified as a likely source of this year’s previous E. coli outbreak linked to romaine from the Yuma, Arizona, region.

After the Yuma outbreak, growers in California and Arizona increased the buffer zones between animal lots and produce fields, from 400 feet to 1,200 feet. Teressa Lopez, an administrator with the Arizona Leafy Green Marketing Agreement, also noted that growers in the state started treating water that runs near animal lots. The treatment, which kills pathogens, is used on water that is going to be used on produce.

Is more regulation coming?

The Food and Drug Administration has new rules to step up the safety of produce, but the implementation is staggered and began just recently. The agency has said inspections won’t start until next year.

Sarah Sorscher of the Center for Science in the Public Interest noted the importance of measures such as testing irrigation water. But a water-testing requirement has been contested and postponed, given the limited availability of tests that can specifically detect the harmful types of E. coli. Ultimately, that rule may not be implemented, Sorcher said.

Why can’t i just wash my romaine?

Washing doesn’t kill germs like the heat from cooking does. That’s why health officials are warning against all romaine.

According to a 2013 U.S. government report , leafy greens such as lettuce and spinach are the biggest source of food poisoning.

“Any product that we don’t have a cooking step is a bigger issue,” said Martin Wiedmann, a professor of food safety at Cornell.

Then when can i have salad again?

It’s not clear when it will be OK to eat romaine again. Public health officials would want to be able to identify the source of the contamination or see the reported illnesses stop. Romaine has a shelf life of 21 days.

Romaine sold in the U.S. comes from different regions at different times of year. So while the romaine lettuce linked to the E. coli outbreak earlier this year was from Arizona, romaine lettuce on shelves now is mostly from California, regulators said.

Harvesting just recently began shifting back to southern California and Arizona, though most of that product has not started shipping, according to Lopez of the Arizona Leafy Green Marketing Agreement. She said suppliers were asked to withdraw products until health officials are confident the pipeline is clear of contaminated romaine.

Besides the romaine outbreak, there’s a long-running widespread salmonella outbreak linked to raw turkey in the U.S.

Raw meat and poultry is allowed to have salmonella because it’s assumed that people will cook it. That’s why regulators aren’t telling people to avoid it, they’re just reminding people to properly handle and cook their holiday birds.

The Associated Press Health & Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

Copyright 2018 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.


Watch the video: CDC Expands E. coli Warning To All Romaine Lettuce (July 2022).


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