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    Why can traceback take so long?

    Hello, this is Julia Stewart, and welcome back to Produce Marketing Association’s new briefing series, “Ask Dr. Bob Whitaker”. PMA is excited to have this opportunity to use high-technology tools to bring you these personal postings from our new chief of technology, Food Science Officer Bob Whitaker.

    Bob, the tomato industry is understandably upset about the ongoing foodborne illness outbreak that has been linked to certain types of fresh tomatoes. The Food and Drug Administration has been working for more than 10 days to identify the source of the contaminated tomatoes – but in the meantime many retailers and foodservice operators have pulled all tomatoes from their shelves and menus. Everyone in the produce industry puts public health and the health of our consumer customers, first and foremost. But now even safe production areas and products are being shunned by the market. Some production areas are at risk of losing their entire season, and tens of millions of dollars. Meanwhile, consumers are missing out on one of the true joys of summer eating, fresh tomatoes.

    Can you explain why a traceback can take so long?

    Dr. Bob Whitaker:

    First let me say that at its very core, traceback is an investigation. It relies on data gathering and analysis. That process is performed under the simultaneous pressures of having to communicate sufficiently to protect public health and perhaps removing potentially contaminated products, while at the same time being mindful to minimize disruption to food supplies – and it has to be 100 percent accurate.

    As state health agencies and/or CDC determine that an unusual illness pattern is emerging and they identify a causative microorganism, it triggers epidemiological studies to determine how people are becoming infected. Often this is called “identifying the vehicle”. One of the key questions epidemiologists ask patients is where they contacted the food product in question – be it restaurant, retail store, family picnic, school, church social, friend’s house, et cetera. They use a questionnaire to guide their questioning, but you can imagine how difficult this can be. Just think about it, can you remember what you had for dinner three weeks ago Wednesday? The epidemiologist is looking for the patient who can – and they need to be able to tell them where they purchased or ate the food. This can take several days or even weeks to find a handful of credible patients who can. When the epidemiologist can credibly link the patient with the food vehicle and a point of service location, it becomes an investigative leg for traceback.

    FDA and state investigators begin traceback by visiting the points of service looking to establish a link between the food product and its source. As we all know, stores and restaurants often have multiple sources of any one item, so the investigators need to determine what suppliers potentially provided the item under examination. They also need to assess the time periods and quantities of product involved, along with the various types or varieties of the product — in the case of tomatoes, you might have, round red, cherries, Romas or plums, grape, on-the-vine, heirlooms, yellows, et cetera.

    The efficiency of this process is largely based on whether the investigators can get access to complete purchase and receipt records from the point of service – in other words, this is where the quality of the supply chain’s record keeping becomes important. As the investigators visit multiple sites identified by credible patients, they can look for common threads, for example suppliers that are common to the most of the points of service. At this point, the investigators can contact those common suppliers and begin tracing the product back to the production site. FDA inspectors generally visit the distribution, production or supply facilities to interview the operators, and review records to be sure they tie in with the point of service documents. Again, the efficiency and the time needed to complete this task are often dependent on the completeness of the supplier’s receiving and shipping records. This process becomes further complicated when we have multiple states involved like we do currently, and while new cases are still being reported. The matter is made even more difficult because the produce industry is so complex. We can have many links in the distribution chain, from growers to packers, distributors, wholesalers, re-packers, processors, cooler, distribution centers and end users – so trackback can be challenging.

    Early on in this most recent tomato outbreak, FDA contacted industry trade and commodity groups to help them understand how tomatoes move through commerce from grower to consumer. That tomato production is in a seasonal transition during the traceback of this outbreak likely complicated the situation. To date this tomato traceback has involved numerous site visits and thousands of pages of shipping and receiving records that must be reviewed and analyzed by FDA. This unfortunately, and frustratingly, takes time. It can be thought of as like solving a puzzle or moving through one of those kid’s mazes – except that before you can turn right or left, you must use the data you have in hand to guide your decision. It is important for the traceback investigators to thoroughly review the documentation because if they fail to do so, they can take a wrong turn in the investigative maze and waste time and valuable resources. I think that this tomato outbreak has been unusual in that, while this investigative traceback has been going on, the FDA has also been identifying locations the tomatoes could not have come from. They have done this by looking at the dates when illness started to appear and when certain areas of the country were producing tomatoes. Generally, if an area started production after the bulk of the illnesses occurred and they can document it, then it is not likely to be a source of the outbreak, and has been removed from the alert. So at least we’ve been able to exclude products and production areas along the way.

    Once the FDA and state investigators identify a region and/or a supplier, they then begin the task of searching for a cause of the contamination. They often inspect the site and facilities and evaluate production records to verify that a food safety program was in place and was being followed as required by the plan. They may also sample raw or finished products (especially if the same lots are still available), and may wish to take environmental samples from fields, equipment, agricultural inputs and water for microbial testing. They may also interview employees and take personal health histories to see whether anyone who may have contacted the product had a similar infection. Their goal is to try to find the cause for contamination, so it can be mitigated and the industry can learn from it – and so public health can be protected.

    As of today, FDA continues to work to identify the specific region and supplier where the contamination originally occurred. FDA has a process they must follow and a legal responsibility to make decisions based on the data they collect. This traceback started on or about June 2nd and so it has been ongoing, round the clock for about 10 days. This is agonizingly slow for those still included in the FDA alert with millions of dollars tied up in aging tomatoes that cannot be sold - but the first and foremost role of FDA is public health, and they cannot release product until the traceback is complete. We remain hopeful that FDA will have the source location identified soon.

    I hope this helps everybody understand the elements and time requirements of traceback and why traceback isn’t just a matter of going to a store or restaurant where a patient says he or she ate, and finding the supplier responsible.


    When this particular situation is over, PMA will meet with FDA to talk about how the agency can improve its produce traceback procedures, and how the industry can facilitate that process. We’ve been able to help a lot this time, but we think that there is even more than we can do on that end. And it is no secret that FDA is underfunded and understaffed, and PMA has long advocated for more funding for the agency. Here’s where our audience members can help. If you haven’t already signed up for our grassroots advocacy group called GROW, please email your contact information to grow@pma.com — and the next time that our government relations team asks you to call Congress about FDA funding, please pick up that phone promptly. Thank you, and we’ll see you next time!

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