Uncertainty

  • Posted: November 19th, 2011 - 3:28pm by Doug Powell

    It’s not easy being a food safety investigator in the face of deep uncertainty.

    So says Ron Doering, a past president of the Canadian Food Inspection Agency who practices food law in the Ottawa offices of Gowling Lafleur Henderson, in his latest Food Law column.

    In the U.S., the largest foodborne outbreak in the last decade involved a rare strain of Salmonella Saintpaul thought to originate from tomatoes. The Food and Drug Administration (FDA) acted quickly, providing a public warning to avoid eating tomatoes until its investigation was complete. After several weeks and hundreds of tests and interviews, the FDA concluded that the problem was likely not tomatoes but rather hot peppers. Politicians rushed to microphones attacking the FDA for “destroying” the tomato industry. Of course, these are the same people who would have been outraged if tomatoes had been the source of the Salmonella and the FDA had not acted quickly.

    While the FDA probably did the right things in the face of so much uncertainty, they should have communicated better. Tracing the source of foodborne illnesses is very complicated, especially for produce like tomatoes where there are no bar codes, no packages, and they are quickly consumed, often with other produce.

    In the EU, the largest foodborne illness outbreak in the last decade, and one of the developed world’s most severe in modern times, took place this summer when a very rare strain of E. coli (O104:H4) got into the European food supply.

    The first death was reported on May 24. The next day, the Robert Koch Institute announced that the early epidemiology indicated that the likely culprit was cucumbers, tomatoes or green salads. And later that day German officials announced that the rare strain had been found in the stools of five of the sick patients. The following day a German state-level agency announced triumphantly that it had found E. coli on Spanish cucumbers, though it had not yet tested for the strain.

    On May 31, after testing for the strain, it was announced that the cucumbers were not to blame, by which time, of course, the Spanish cucumber industry was destroyed and German vegetable growers were suffering losses of $2.8 million per day as consumers quit eating all salads. Finally, on June 5 it was reported that “initial tests” (it was not tests, it was the result of epidemiological tracing) revealed that sprouts grown on an organic farm in Germany were “likely” the source of the problem, even though they couldn’t find a smoking sprout on the farm. Then on June 12 several victims of the O104 strain fell ill in France. They had no connection to the German organic farm. Attention turned to seeds, with the French blaming the British (I’m not making this up). Finally, on June 29 tracing determined the source of the problem as sprout seeds imported from Egypt in 2009. By this time there had been more than 50 deaths and well over 4,300 people seriously ill, including approximately 900 cases of patients with permanent kidney damage.

    In both cases, with the benefit of hindsight, academics and the media roundly criticized the regulators as incompetent.

    In a detailed review of the EU sprouts case, Peter Sandman, an expert on risk communication, concluded that the main failure of the regulators was in not being more forceful in proclaiming in their risk messaging the level of uncertainty in the case.

    To me it seems there is a more basic problem, and it flows from the use of the language of risk, because “risk” disguises the deep uncertainty inherent in complex cases like these. These regulators were dealing with uncertainty, not risk — they were engaged in crisis management, not risk management.

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  • Posted: July 12th, 2009 - 2:15pm by Doug Powell

    “If only” is often how statements begin by food safety wannabes who are sure they have stumbled upon a vast conspiracy meant to subjugate society.

    If only Monsanto didn’t genetically-engineer seeds …

    If only products like milk were served raw and natural …

    If only cattle were fed grass, there would be no E. coli O157:H7.

    When someone makes such proclamations, or says they speak fact, usually with an air of authority, I immediately think that person is full of it. People who say “trust me” are immediately untrustworthy.

    Megan Jacob, Todd Callaway, and T.G. Nagaraja of Kansas State University write about the dietary interactions and interventions affecting Escherichia coli O157 colonization and shedding in cattle in an upcoming issue of Foodborne Pathogens and Disease. It’s not a movie, not a blog, not a pulp fiction, so they sorta have to get it right. And they do, when they write:

    “The specific mechanisms responsible for increased or decreased E. coli O157 shedding or survival are not known … results of studies are conflicting or not repeatable, which speaks to the complexity of the hindgut ecosystem, variation in animal feed utilization, and variation within feed products.”

    The complete abstract is below.

    Escherichia coli O157 is an important foodborne pathogen affecting human health and the beef cattle industry. Contamination of carcasses at slaughter is correlated to the prevalence of E. coli O157 in cattle feces. Many associations have been made between dietary factors and E. coli O157 prevalence in cattle feces. Preharvest interventions, such as diet management, could reduce the fecal prevalence and diminish the impact of this adulterant. Dietary influences, including grain type and processing method, forage quality, and distillers grains have all been associated with E. coli O157 prevalence. In addition, several plant compounds, including phenolic acids and essential oils, have been proposed as in-feed intervention strategies. The specific mechanisms responsible for increased or decreased E. coli O157 shedding or survival are not known but are often attributed to changes in hindgut ecology induced by diet types. Some interventions may have a direct bacterial effect. Frequently, results of studies are conflicting or not repeatable, which speaks to the complexity of the hindgut ecosystem, variation in animal feed utilization, and variation within feed products. Still, understanding specific mechanisms, driven by diet influences, responsible for E. coli O157 shedding will aid in the development and implementation of better and practical preharvest intervention strategies.

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