E. coli Outbreak: Questions & Answers

Information From Food Safety Expert and CDC About E. coli Outbreak and Fresh Produce

From the WebMD Archives

Sept. 15, 2006 -- The FDA is warning consumers not to eat bagged fresh spinach as it probes a multistate outbreak of E. coli linked to at least one death and scores of illnesses.

The warning currently applies to all bagged fresh spinach, regardless of whether it was conventionally or organically grown.

Here are three questions and answers about E. coli, based on information from the CDC:

Q. What is E. coli?

A. E. coli is a bacterium. There are hundreds of strains of E. coli. The strain involved in the current outbreak is E. coli 0157:H7.

Q. What are the health risks of E. coli 0157:H7?

This strain of E. coli can cause abdominal cramping and diarrhea, often with bloody stools. Most adults recover fully in about a week.

But it can also lead to a serious complication called hemolytic uremic syndrome (HUS) which causes kidney failure. Young children and the elderly are at particular risk for this complication.

Q. How common are E. coli outbreaks?

This particular strain of E. coli causes an estimated 61 deaths and 73,000 cases of infection in the U.S. annually, according to the CDC.

Most past infections have been linked to undercooked ground beef.

Other culprits have been sprouts, lettuce, salami, unpasteurized milk and juice, and swimming in or drinking sewage-contaminated water, according to the CDC.

Perspective of a Food Safety Expert

WebMD also spoke with Richard H. Linton, PhD, a professor of food safety and director of the Center for Food Safety Engineering at Purdue University.

Following are eight questions about bagged fresh produce and Linton's answers.

Q. Should all bagged fresh produce be avoided?

A. No. We're just talking about spinach at this point in time.

Q. Should all bagged fresh produce be washed at home, even if it says "prewashed"?

A. I think there's a very minimal effect in what a consumer can do from a washing standpoint, other than what was done at a manufacturing facility.

Normally, these things are triple-washed at a manufacturing facility. We can recommend to consumers that they have an additional wash, but as a scientist, I can tell you the effect will be minimal.


Q. But there's no reason not to do another wash at home?

A. There's no reason not to, no. But the reason that FDA is asking for all of these products to come back is that they recognize that the washing step, if the organism was present, is not 100% effective.

Q. What about once this outbreak is resolved? Is it a good idea to get in the habit of doing another rinse at home?

A. I think it's one small level of assurance that consumers can use, but it is in no way a guarantee. I think it's a very minimal effect, and I don't want consumers to believe that their washing is going to take care of all of the problems for a fresh-cut product that's been bagged.

Certainly, that recommendation is very important for a product that's not packaged -- for a product that's in its whole state. Consumers can really make a difference in the wash.

Q. What's the best way to wash produce that is loose, not prepackaged?

A. Unfortunately, no one has the silver bullet for washing produce to assure that it's safe.

Different agencies will recommend that fruit and vegetables are washed with warm, soapy water, or that they're simply rinsed.

I've worked on produce for almost 15 years, and I can tell you that most of these washing interventions have a very minimal effect. They might remove 100 to 1,000 microorganisms on the surface. And when we look for something to be truly effective, we look at something that is 100,000-fold or a million-fold kill.

Unfortunately, it doesn't matter what the wash is, there's a limitation into what we can actually remove.

Q. Is there something about spinach that could make it more likely to carry E. coli than other bagged fresh produce? Is there anything about spinach or is that what we just happen to be seeing right now?

A. It just happens to be what we see right now.

Leafy vegetables, just because of the way in which they're structured and configured, makes organisms find spots where they're more difficult to remove, compared to, like, a tomato, which has a much smoother surface.


Q. Does cooking kill E. coli?

A. Yes.

Q. Is there a certain temperature it has to get to, or length of time?

A. To be totally safe, 160 to 165 degrees Fahrenheit for a few seconds would be adequate.

But the recommendation that comes out from FDA is to take the spinach and return it to the place at which you purchased it.

They want it to be returned for a couple of reasons. The first reason is to protect the consumer. The second reason is from a surveillance standpoint to find out where this is coming from. If they have bagged spinach that's returned, it can be tested and they can start their process of trying to identify the initial source of contamination.

WebMD Health News Reviewed by Louise Chang, MD on September 15, 2006


SOURCES: News release, FDA. Associated Press. CDC: "Escherichia coli 0157:H7." Richard H. Linton, PhD, professor of Food Safety, director, Center for Food Safety Engineering, Purdue University.

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