by Marion Nestle

Currently browsing posts about: E.coli

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.

FoodSafetyNews.com 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.

FoodQualityNews.com 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.

Apr 20 2010

Food safety progress: some good news, some not

On April 16, the CDC published its annual report on foodborne illnesses in a ten-state sample.  CDC writes in passive voice and it’s a struggle to get to the good news:

In comparison with the first 3 years of surveillance (1996–1998), sustained declines in the reported incidence of infections caused by Campylobacter, Listeria, Salmonella, Shiga toxin-producing Escherichia coli (STEC) O157, Shigella, and Yersinia were observed…Compared with the preceding 3 years (2006–2008), significant decreases in the reported incidence of Shigella and STEC O157 infections were observed.

Some consumer groups urge caution in interpreting the drop in toxic E. coli cases, as previous drops have rebounded.

And then there’s the not-so-good news: “The incidence of Vibrio infection continued to increase.”

Vibrio infections reflect the oyster problem I talked about last fall.  The gulf oyster industry is still fighting the FDA over methods to decrease these preventable infections.  Perhaps this bad news will encourage the FDA to get busy and regulate oyster safety.

The Inspector General of the Department of Health and Human Services is worried about FDA’s inspection ability:

  • On average, FDA inspects less than a quarter of food facilities each year, and the number of facilities inspected has declined over time.
  • Fifty-six percent of food facilities have gone 5 or more years without an FDA inspection.
  • The number of facilities that received OAI [Official Action Indicated] classifications has declined over time.  In addition, nearly three-quarters of the facilities that received OAI classifications in FY 2008 had a history of violations. Two percent of facilities that received OAI classifications refused to grant FDA officials access to their records.
  • FDA took regulatory action against 46 percent of the facilities with initial OAI classifications; for the remainder, FDA either lowered the classification or took no regulatory action.
  • For 36 percent of the facilities with OAI classifications in FY 2007, FDA took no additional steps to ensure that the violations were corrected.

This is also bad news.  Worse, is congressional inaction over food safety.  The House passed its food safety bill–one designed to fix the FDA–last August.  The Senate has yet to deal with its version.  Can food safety wait?  No, it must not.

Feb 12 2010

Bagged salads: safe or not?

Consumers Union tested a couple of hundred samples of bagged salads, organic and not.   The results? Nearly 40% contained levels of coliform bacteria higher than safety standards.  Coliforms indicate fecal contamination.  This is disgusting to think about but does not make anyone sick.

So the Consumers Union results could be reassuring or not, depending on whether you are an optimist or pessimist.  Yes, the coliform levels were high, but none of the samples contained toxic forms of E. coli, such as O157:H7.

Still, the high frequency suggests that bagged salads need either much better washing or much better maintenance of the cold chain (so the bacteria don’t grow), or both.  If nothing else, the report is a good reason why it’s important to give bagged salads a thorough washing before you eat them or serve them to anyone.

Consumers Union makes a big point of the need to get food safety legislation moving.  The House passed its version of a bill at the end of last July.  The Senate hasn’t budged on its bill.   In the meantime, we still have major national outbreaks and recalls.

The most recent?  225 people in 44 states plus the District of Columbia ill from Salmonella because they ate salami coated with contaminated black pepper. We still don’t have a food safety system that works.  We need one fast.

Jan 14 2010

On the food safety front…

Cookie dough: Nestlé reports that it has again found E. coli O157:H7 in its cookie dough and will now be heating the flour before using (see, the New York Times account, and the report from FoodProductionDaily.com.

This is odd.  How do they know that the flour is the carrier?   As I discussed in previous posts, the source of the contaminating bacteria has either not been found or not announced.  This action implies that the company must think the flour is at fault.  Let’s hope so.  We certainly don’t want the chocolate bits to be the carrier.

FDA news: The FDA announced yesterday that it has appointed Michael Taylor as Deputy Commissioner for Foods.  This is a new office at FDA which, if Congress ever gets around to passing it, will be responsible for implementing the preventive control provisions of the food safety bill.  Peventive control, I’ve just learned, is the new euphemism for HACCP (Hazard Analysis and Critical Control Point).

As I describe in a previous post, Mr. Taylor’s appointment is not without controversy but his expertise in food safety runs deep.  I think this is a good move for FDA.

Update January 15: And here is what the Washington Post and the New York Times have to say about Taylor’s appointment.  I’m quoted in the Post story.

He is the quintessential revolving door,” said Marion Nestle, a professor of nutrition, food studies and public health at New York University. Taylor’s support for BGH and Monsanto’s other genetically modified products at the FDA was “questionable,” she said. “On the other hand, when he went to USDA, what he did there was absolutely heroic. He’s been very strong on food safety.

Dec 30 2009

The latest recall: mechanically tenderized beef

I am, as always, indebted to Bill Marler for his ongoing commentary – often with slide shows – on recalls of foods contaminated with E. coli O157:H7 and other nasty bugs.  He offers ongoing comments about the Christmas eve recall of 248,000 pounds of needle-tenderized steaks.

He points out that the recall now affects people in several states and that the meat was intended for several chain restaurants.   The contaminated meat, produced in Oklahoma, has sickened at least 19 people in 16 states.

Mechanically tenderized “non-intact” beef?  Uh oh.  The great thing about intact steak is that harmful contaminants are on the outside surface; the bacteria get killed by the high heat of searing the outside surface.  You don’t have to worry about the safety of intact steak because its insides are relatively sterile.  But if the steak is pre-treated to tenderize it, watch out!  Tenderizing can drive harmful bacteria right into the interior where they won’t get killed unless the steak is thoroughly cooked.

To explain the problem, Marler posts a slide show from Dave Boxrud.  Here is one of Boxrud’s illustrations:

Photo from David Boxrud's slide show on the Marler Blog site

Marler provides links to documents showing that the USDA has received plenty of recent warnings about the dangers of undercooked non-intact beef.  This is no surprise.  In my 2003 book, Safe Food (coming out in a new edition in 2010), I discuss the USDA’s “testing gap” with respect to nonintact beef.  In 1999, the USDA said that it wanted to extend its testing requirements for ground beef to mechanically tenderized beef that might be contaminated with E. coli O157:H7.

In Safe Food, I explain how the beef industry reacted with “shock, disbelief, and anger” to the USDA’s safety proposal.  One industry representative accused the USDA of taking “another step in this administration’s obfuscation of the impeachment activities.” Those activities, of course, referred to the scandal then involving President Clinton and the White House intern, Monica Lewinsky.

Then, the meat industry’s position was that pathogens were inherent in raw meat, cooking kills them, and testing would put the industry out of business. Ten years later, the industry position hasn’t budged. The Washington Post (December 30) quotes beef industry representatives arguing that mechanical tenderizing poses no particular health problems.

According to Food Chemical News (September 28), Congressional representative Rosa DeLauro (Dem-CT), who chairs the House appropriations agriculture subcommittee, has called on USDA to take immediate action to require labeling of meat that has been mechanically tenderized.

And USA Today (December 30) has produced another long investigative report on the safety of school meals, this one citing plenty of examples of companies that successfully produce or serve safe meat and of countries that do food safety better than we do.  In the meantime, the food safety bill is still stuck in Congress.  Let’s hope that it gets moving early in 2010.

Addendum: The New York Times (online December 30) also is interested in beef produced for the school lunch program.  Its reporters investigated safety problems with beef trimmings that had been injected with ammonia to kill bacteria.    Two things about the beef trimmings are especially interesting.  One person is quoted in the article referring to them as “pink slime.”  And they used to be used for pet foods until meat packers figured out that selling them to USDA for school lunches was more profitable.

As for the ammonia treatment: surely this is not the same stuff used to clean bathrooms?  Apparently so.  But using it is tricky.  You have to inject enough ammonia to kill bacteria but if you do the meat smells like an ammonia-treated bathroom.  If you don’t want the meat to smell, you can’t use as much.  But if you don’t use as much, you get Salmonella. This, alas, is another example of regulations not working.

Congress: pass the food safety bill and then start working on a single food safety agency!

Update January 7: The CDC has posted information on its investigation of this outbreak on its website.