by Marion Nestle

Currently browsing posts about: E.coli

May 12 2016

Chipotle’s food safety issues: the saga continues

Food Safety News continues to be incredulous at Chipotle’s apparent denial of responsibility for the safety of food served in its outlets.

For sure, what has happened at Chipotle restaurants is unusual—illnesses caused by multiple toxic microbes at multiple locations:

  • Seattle — E. coli O157:H7, July 2015, five sick people, source unknown;
  • Simi Valley, Calif. — Norovirus, August 2015, 234 people, source was sick employee;
  • Minnesota — Salmonella Newport, August and September 2015, 64 sick people, source was tomatoes but it remains unclear  at what point in the field-to-fork chain the pathogen was introduced;
  • Nine states — E. coli O26, began October 2015 and declared over Feb. 1, 55 sick people, source unknown, states involved are California, Delaware, Illinois, Kentucky, Maryland, Minnesota, New York, Ohio, Oregon, Pennsylvania and Washington; and
  • Three states — E. coli O26, began December 2015 declared over Feb. 1, five sick people, source unknown, states involved are Kansas, Oklahoma and Nebraska; and closing out in
  • Boston — Norovirus in December, 151 sickened.

Chipotle did the obvious right thing.  It brought on board the most experienced and highly regarded food safety experts: Mansour Samadpour (he has a food safety consulting company), James Marsden (to head up its food safety initiatives), Dave Theno (formerly of Jack in the Box) and David Acheson (former FDA food safety official).

Perhaps before they had time to weigh in, Chipotle’s counsel wrote a letter to the CDC complaining about the way the agency was conducting its investigation.

The CDC recently responded in no uncertain terms as Food Safety News discussed.

Food safety lawyer Bill Marler says:

My thought:  “In 23 years being involved with every major food illness outbreak in the US, I have never seen a company take on the CDC or public health in this manner.  Frankly, it is bizarre given that Chipotle was involved in multiple Salmonella, Norovirus and E. coli cases in 2015.  As the CDC states in its responsive letter, it has to protect the public health and that is what it did.”

His view of the score: CDC 1, Chipotle Lawyer 0.

Chipotle’s food safety consultants have their work cut out for them.  Let’s hope they figure out the problem and find ways to solve it—soon.

Dec 28 2015

Chipotle’s food safety problems: an update

I’m fascinated by reports of Chipotle’s ongoing problems with foodborne illness.

  • The main interest of the press in these episodes is their effect on Chipotle’s stock prices.
  • The outbreaks have been linked to a bunch of different pathogens: E. coli O157:H7, E. coli STEC O26, Salmonella, norovirus, and, possibly, hepatitis A.  This means they are due to different causes at different outlets.
  • The food, foods, or individuals responsible for these outbreaks are uncertain, making them hard to know how to prevent.
  • Hence: conspiracy theories.

The outbreaks

The most recent CDC report (December 21) counts 53 cases of E. coli 026 from 9 states, with 20 hospitalizations.

12-18-2015: Epi Cruve: Persons infected with the outbreak strain of E. coli O26, by date of illness onset

The FDA reports (December 22) that there are 5 more recent cases of illness caused by a different type of E. coli 026 among people eating at Chipotle.

Food Safety News summarizes the previous Chipotle outbreaks.

  • Seattle: July 2015, 5 people sick from E. coli O157:H7, from unknown food source.
  • Simi Valley, CA: August 2015, more than 230 sick from norovirus (most likely from an ill worker).
  • Minnesota: August and September 2015, 64 people sick from Salmonella Newport (tomatoes?).
  • Boston: December 2015, at least 136 people sick from norovirus.

The consequences

  • Nearly 500 people have become ill after eating in a Chipotle since July this year.
  • Stock prices are down 30 percent from a high of $757.77 in August.

The conspiracy theory

The title says it all: “ANALYSIS: Chipotle is a victim of corporate sabotage… biotech industry food terrorists are planting e.coli in retaliation for restaurant’s anti-GMO menu.”

I don’t think so.

You don’t need conspiracy theories to explain poorly designed and executed food safety procedures.

What is to be done?

The New York Times attributes the inability to identify the food source to Chipotle’s record-keeping:

One of the challenges here has been that we have been able to identify the restaurants where people ate, but because of the way Chipotle does its record-keeping, we have been unable to figure out what food is in common across all those restaurants,” said Dr. Ian Williams, chief of the outbreak response and prevention branch of the C.D.C.

That, at least, should be an easy fix.

For the rest, Chipotle has initiated a new food safety program, and has recruited a leading food safety expert, Mansour Samadpour, to set it up.  I met Samadpour at Earthbound Farms when he was helping that company prevent further problems after the spinach outbreak of 2006.  He knows what he his doing.

Chipotle needs to follow his advice—in letter and in spirit.

Food safety lawyer Bill Marler advises Chipotle to follow a 12-step program to create an effective culture of food safety from top down and bottom up within the company.  For example, he advises the company’s CEO, Steve Ells to say:

  • It is time to have a culture of food safety added to the “integrity” of the food. I have now learned that bacteria and viruses do not care a whit if my food’s ingredients are organic, sustainable, non-GMO and humanely raised.
  • I am going to hire a vice-president of Food Safety. That person will report directly to me and to the Board of Directors. Like Dave Theno being brought in to address the Jack-in-the-Box crisis of 1993, this person will have the resources and access to decision makers to create a culture of food safety from the top down.
  • The company’s new mantra – “Safe Food with Integrity” – will be completely transparent and shared with all – including our competitors.

Will Ells take his advice?  I hope so.

Nov 30 2015

Chipotle’s E. coli outbreak is nearly over, still a mystery

The CDC’s latest update on the food safety problems at Chipotle says whatever food or ingredient caused 45 people to become ill with E. coli is still unknown.

Bill Marler, the food safety attorney who tracks such things, offers a history of previous Chipotle outbreaks from 2008-2015; these involved Norovirus, Salmonella, hepatitis A, campylobacter, and now an STEC (Shiga Toxin-Producing E. coli).

Chipotle closed some of its outlets in the Northwest, but then reopened.

Steve Ells, Chipotle’s CEO, placed an ad in the New York Times, promising to do everything possible to prevent this from happening again.

Screen Shot 2015-11-14 at 9.39.40 AM

This got Bill Marler to ask: Is this Chipotle’s 2-b-4 moment?

We only make dramatic changes when we’ve been hit in the head with a 2-by-4 once or twice. Hopefully for Chipotle, this is their 2-by-4 moment.

The presence of E. coli indicates fecal contamination of some ingredient or food that was not cooked or not cooked sufficiently (cooking kills bacteria).  But from what animal,where, and when?

Chipotle needs to check every ingredient it sources, as well as every process involved in preparing and serving the foods.  If standard safety procedures aren’t already in place, this is a big job.

Let’s hope the CDC finds out what caused this outbreak, and soon.

Jan 16 2012

The latest in meat safety: another form of zapping?

Bacterial contamination of meat is an ongoing problem and everyone wishes for an easy fix—one that does not require meat producers and packers to prevent contamination.

Irradiation works, but raises feasibility and other concerns.

How about electrocution?

Food Production Daily reports that hitting meat with electrical current reduces toxic E. coli O157:H7 on meat surfaces by 2 log units.

The research report says researchers inoculated meat with the bacteria and then applied electrical current.  But by inoculation they must mean just on the surface, because they only counted surface bacteria.

Surface bacteria, alas, are not the problem.  Searing meat effectively kills surface bacteria.   Bacteria in the interior (of hamburger, for example) survive unless the meat is well cooked.

And 2 log units is unlikely to be good enough for bacteria that cause harm at low doses, as this kind does.  The FDA requires a 5 log reduction for fresh juices, for example.

I wish researchers would apply their talents to figuring out how to keep toxic bacteria from getting into and onto animals in the first place.  Then we wouldn’t have to worry about designing techno-fixes to deal with contaminated meat.


Jun 11 2011

The science and politics of E. coli in sprouts

German authorities now say that  sprouts grown on an organic farm in Lower Saxony are the source of their E. coli O104:H4 outbreak, now responsible for more than 30 deaths and 3,000 illnesses, 750 of them severe kidney disease.

The epidemiological studies point to sprouts after all.

Sprouts, as I mentioned in an earlier post, are a prime suspect in microbial outbreaks.   They have been implicated in many outbreaks in the United States.  This is because sprouts are sprouted from minute seeds that are hard to clean, as shown in this microscopic view:




As Food Safety News explains in a long discussion of this problem, the seeds need to be dumped in bleach to kill bacteria.  It’s also a really good idea to test the wash water to make sure it is free of pathogens.

The seeds are sprouted in water at room temperature, “a warm, moist climate — just perfect for a bacteria’s social life and subsequent reproduction.”

The FDA has been aware of this problem for a long time, as shown by this brief chronology:

The Food Safety Modernization act passed last year finally gives FDA the authority to require food safety controls for sprouts.

The German outbreak ought to be a wakeup call for this industry in the United States.  Sellers of bean sprouts market them as health foods but say little about how unsafe they are if eaten raw.

It also ought to be a wakeup call for consumers.  If you aren’t absolutely sure the seeds come from a clean source, cook your sprouts.

Jun 6 2011

The German E. coli outbreak: now it’s sprouts?

I haven’t said anything about the E. coli 0104 crisis in Germany up to now because I’ve been waiting for the evidence.  Without evidence, the source of the outbreak remains uncertain.

Yesterday, the German minister of agriculture announced that sprouts are the cause.  But are they?

What  is known without question is that the outbreak is deadly serious.  Bill Marler reports these shocking numbers as of June 5:

Deaths = 22 (21 in Germany, 1 in Sweden)

Illnesses = 2,243 (2,153 in Germany, and 90 more in 10 other European nations and the U.S.)

Cases of Hemolytic Uremia Syndrome (HUS) = 627

Why shocking?  This is a devastating disease, excruciatingly painful, with a high probability of causing lifelong complications.  And the disease is almost entirely preventable by following standard food safety procedures.

The idea that the cause is sprouts, and German sprouts at that, comes as a surprise.  Why?  First, sprouts are a frequent cause of foodborne illness and should have been high on the list of suspected foods.  Second, sprouts did not turn up in the case-control studies.

Instead, investigators examined cucumbers, lettuce, and tomatoes (and, in the process, put Spanish cucumber producers out of business).  As Marler explains, the German authorities didn’t want to take a chance, given the results of their investigation.

The case-control investigation was conducted by the Robert Koch Institute, the German equivalent of our CDC.

  • The cases: From May 29 to June 2, investigators interviewed 46 affected patients from Bremen, Hamburg and Lübeck about the foods they had eaten.
  • The controls: They interviewed 2,100 people who were not sick but were of similar age group, sex and region of residence.
  • The results:

Food Reported Eaten         % By Cases     % By Controls

Lettuce                                        84                           47

Cucumbers                                 75                           50

Tomatoes                                   80                            63

95% of the Cases had eaten at least one of the three vegetables.

This evidence strongly implicates these vegetables.  But did they not look for sprouts?

In another related study of people from a Frankfurt business company who had become ill, those who had eaten from the salad bar in the company cafeteria had a 7-fold increased risk of developing bloody diarrhea than those who had not.  No such association was seen for other foods investigated, such as dessert, fruit and asparagus.  Sprouts are not mentioned.  How come?

In trying to figure out what’s going on here, a BBC World News report raises even more questions (my emphasis):

The agriculture minister for Lower Saxony, Gert Lindemann, said there was a clear trail of evidence pointing to a plant nursery south of Hamburg [as the source of the contaminated sprouts].

The nursery has been closed, though officials say the outbreak’s source cannot yet be definitively confirmed.

…Mr Lindemann said epidemiological studies all seemed to point to the plant nursery in Uelzen in the state of Lower Saxony, about 100km (62m) south of Hamburg – though official tests had not yet shown the presence of the bacteria there.

“Further evidence has emerged which points to a plant nursery in Uelzen as the source of the EHEC cases, or at least one of the sources,” he said.  [What evidence?]

…Gert Hahne, a spokesman for the Lower Saxony agriculture ministry, earlier told the Associated Press news agency that many restaurants in which people ate before becoming ill had recently taken delivery of the sprouts. [Guilt by association]

He said authorities would still maintain a warning against eating tomatoes, cucumbers or lettuce.

The health ministry in Berlin said it was still waiting for results from tests on the beansprouts, Germany’s DPA news agency reported.

And the head of the Robert Koch Institute (RKI), Germany’s national disease centre, was also reported as saying that the cause of the outbreak could not yet be confirmed.

So: are sprouts the cause?

By this time, the outbreak is slowing down as the contaminated foods make their way through the food supply.

Could this happen here?  You bet.

If ever there was a time to give the FDA more resources, now is it.  The FDA now has the authority to impose standard food safety procedures on food producers and to require safety measures for the foods we import.   But Congress wants to cut the agency’s budget, and badly.

Now would be a good time to let congressional representatives know that we need a stronger FDA.   And while you are at it, let the USDA know that you think it would be a good idea to regulate other forms of toxic E. coli as adulterants in the same way they regulate E. coli 0157:H7. There is plenty government could do right now to protect us from outbreaks like this one.

A word about sprouts:

How come sprouts are such frequent sources of food safety problems?

Sprouts are grown from tiny seeds that are impossible to wash thoroughly enough to ensure that they are free of harmful bacteria.  The seeds are sprouted in water that must be changed several times a day.  This water is an excellent growth medium for bacteria.  That is why FDA guidance says sprout producers ought to test the wash water for harmful bacteria.

Under the new legislation, the FDA has the authority to enforce this guidance.  But does it have adequate personnel?  Unlikely, given the current stance in Congress.

This just in:  No, it’s not sprouts, according to this bulletin from Food Chemical News:

The latest news, reported this morning by both the Associated Press and BBC, is that 23 of 40 samples of organic sprouts taken from the Gaetnerhof farm in the Lower Saxony region of Germany have tested negative for the bacteria. Tests on the other samples have yet to be returned.

May 22 2010

The source of E. coli 0145?

Bill Marler, the Seattle attorney who represents victims of food poisonings, consistently urges federal food safety agencies to reveal what they know so consumers can protect themselves from unsafe food.

He is especially annoyed that the FDA has not revealed the name of the farm in Yuma, Arizona, linked to the bagged romaine lettuce that has sickened more than 30 people in several states so far with the unusual form of E. coli, 0145.

Marler knows how to get information (although not always accurate results, apparently – see update below).  He first offered $5,000–and later offered $10,000–as a reward to anyone who revealed the name of the farm before the FDA did (the money goes to charity).  He got two takers. Both identified a particular firm in California as the source.

Update, May 22:  I received a message today from Leslie Krasny, partner in the law firm of  Keller and Heckman, LLP, San Francisco, which represents the farm named by those sources.  She advises me that there is no evidence linking her client’s romaine lettuce to the outbreak and that her client is not even under investigation by the FDA.  She asks that I delete reference to her client, which I have done.  Mr. Marler also has done so.

May 14 2010

Food (un)safety update: E. coli 0145 in Arizona lettuce and more

It’s deja vu all over again with the recent recall of bagged romaine lettuce contaminated with a toxic form of E. coli.  The lettuce came from a central wash-and-bag facility that sent products out to food service companies in several states making about 30 people sick so far.

The one new development is the strain of E. coli: 0145, not O157:H7.  Despite decades of worry that other STECs (Shiga Toxin-producing strains of E. coli) cause serious human illness, state health departments don’t routinely test for 0145.  Clearly, they need to.

The FDA and CDC are both working on this case. has a complete report on the situation to date.  It examines the possible source of 0145 in a three-part series:

Meanwhile, the USDA issued compliance guidelines for reducing Salmonella and Campylobacter in poultry.  That’s nice, but what about STECs?

And the GAO has just issued a new report, FDA Could Strengthen Oversight of Imported Food by Improving Enforcement and Seeking Additional Authorities (don’t you love those titles?).  The report focuses on weaknesses in FDA’s oversight of food imports. has a short but tough summary:

There are about 189,000 registered foreign sites where food is made for sale in the United States, according to the report. Of those, the FDA inspected just 153 in 2008…Meanwhile, the amount of food imported into the United States is increasing, and now accounts for 15 percent of the total food supply, including 60 percent of fresh fruits and vegetables and 80 percent of seafood.

What more evidence do we need for the urgency of passing food safety legislation?  Reminder: the Senate has been sitting on a food safety bill since the House passed it last August.  Apparently, this Congress this food safety can wait.  Tell that to the people who got sick from eating bagged romaine lettuce.

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