Representing the Makers of the World’s Favorite Food, Beverage and Consumer Products

What happened with Chipotle?

December 15, 2015

By: Jennifer McEntire, PhD, Vice President, Science Operations

Most foodborne illnesses, and even most outbreaks, are invisible to the public. Clearly, that has not been the case though with the recent outbreak of E. coli O26 associated with Chipotle restaurants. My friends are talking about it and they are asking me what happened. The reality is we may never know.

The public can’t fathom that despite the fact that 52 people have gotten ill (as of this writing), public health officials still don’t know what food product/ingredient was contaminated. First, bear in mind that people don’t feel sick immediately after they eat a contaminated food. It often takes a couple of days. Investigators need to rely on peoples’ memories to remember exactly what they ate. And at a place such as Chipotle, where you can mix and match ingredients, most of the meals will have one or more ingredients in common.  When so many meals contain beef, chicken, lettuce, tomatoes and rice, how can you tell if the problem is with the beef, chicken, lettuce, tomatoes or the rice?

Actually, there are ways that you can try to tell but they take some time. You can look at the specific shipments of ingredients that each store received, and try to figure out which ingredient they used on a day that someone got sick (e.g., the production date of the tortilla). Then you go to another store where someone got sick and see if the tortillas served when someone fell ill had the same production date as store number 1. You do that for as many stores as possible, with as many ingredients as are suspect, and see if you can find some commonality between the ingredients served in the different stores. This is called a traceback. It’s generally a manual, arduous process that relies on the stores knowing what products they received and when they used them.  If you can narrow the possibilities down to a few ingredients then you move back through the supply chain to see if, for example, all the tomatoes came from one grower, and one field, harvested on a single day. Sometimes you can trace things back easily. Sometimes the product paths don’t line up.

Why can’t you just test the individual ingredients? There are a few challenges to this. One is that contamination is usually a one-time event, meaning that something went wrong in the system and resulted in contamination, but it passed through the system rather quickly. By the time you realize that something happened, and test product, it’s not the same product that ill consumers ate. It’s a fresh batch, and it may not be contaminated. Also, this type of contamination usually occurs at low levels and unevenly. This means that even within a “contaminated” batch the sample that you test may appear to be just fine.

Last night someone asked me if I thought this was an intentional act. His thinking was that because Chipotle is a well known brand that prides itself on the quality of the food it serves, someone with ill intent could have tried to damage this image by causing an outbreak. You can never rule out this possibility, however, given the number of illnesses and the type of organism I think it’s unlikely. If contamination had been intentional I would expect that more people would be sick.

The U.S. has one of the safest food supplies in the world, but invariably from time to time foodborne illnesses and outbreaks are going to occur.  In the case of any outbreak, removing the contaminated ingredient in question from the food supply chain is the first priority, but equally important is trying to figure out how the ingredient became contaminated in the first place.   By identifying how the contamination occurred, the company can put measures in place to help ensure that a similar event does not reoccur.   But unfortunately identifying exactly how any foodborne illness or outbreak occurred, whether in the case of Chipotle or an incident involving another company, will always be a challenge.


Report user misconduct

Filed under: Product Safety

No Comments »

No comments yet.

RSS feed for comments on this post. TrackBack URL

Leave a comment