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Marler Blog Providing Commentary on Food Poisoning Outbreaks & Litigation

The Foodborne Diseases Active Surveillance Network (FoodNet) data for 2009, what does it tell us about actual numbers of ill in the United States at the end of 2010?

And, what will the numbers be in 2011 when the CDC releases new estimates of foodborne disease?

In 1999 the CDC using FoodNet estimated that foodborne diseases caused approximately 76 million illnesses, 325,000 hospitalizations, and 5,000 deaths in the United States each year. These numbers are cited as frequently as we also hear the phrase: “We have the safest food supply in the world.”

In 1999 known pathogens accounted for an estimated 14 million illnesses, 60,000 hospitalizations, and 1,800 deaths. Three pathogens, Salmonella, Listeria, and Toxoplasma, were responsible for 1,500 deaths each year, more than 75% of those caused by known pathogens, while unknown agents accounted for the remaining 62 million illnesses, 265,000 hospitalizations, and 3,200 deaths.

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The CDC qualified the above estimates by noting that the analysis suggested unknown agents account for approximately 81% of foodborne illnesses and hospitalizations and 64% of deaths. The CDC also noted several assumptions that were used to quantify the data. The first assumption concerned the degree of underreporting of bacterial and viral disease. The second assumption concerned the frequency of foodborne transmission for individual pathogens. And, the third assumption concerned the frequency of acute gastroenteritis in the general population.

In 2009 the CDC using FoodNet found a total of 17,468 laboratory-confirmed cases of infection were identified. 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. The incidence of Vibrio infection continued to increase. Compared with the preceding 3 years (2006–2008), significant decreases in the reported incidence of Shigella and STEC O157 infections were observed.

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The coming 2011 estimates are expected to be more refined – primarily due to ten more years of FoodNet data. The numbers are also expected to be adjusted downward – possibly limiting, or eliminating norovirus – as norovirus accounted to a large percentage of the previous estimates. In addition, the continued decease in actual bacterial illnesses, as shown in the 2009 FoodNet data, should also show additional declining numbers.

It will be most interesting to see which groups claim victory over the numbers or how the data is explained – 2011 should be interesting.

  • When will the apologists for the S 510/HR 2749 approach to regulating food safety quit misusing and abusing the out-of-date,1999 Mead study?
    Mead was done by 8 investigators and published in the CDC Journal, “Emerging Infectious Diseases” (EID). It is the estimate of those 8 investigators, NOT the CDC. Despite this fact, apologists almost always cite the source as “the CDC.”
    But, isn’t that ONLY a “technical error?” No. It is one of substance because the CDC is a well respected agency. This characterization of estimate makes it almost immune to scientific criticism. But, in fact, has Mead stood 11 years without criticism by other investigators? Again, the answer is a clear, “No.”
    As pointed out in “Food Safety News” (“Foodborne Illness by the Numbers” by Alex Ferguson http://www.foodsafetynews.com/2010/03/foodborne-illness-by-the-numbers/), exactly 5 years after Mead was published (i.e., September 2004), the same journal published an article by a food safety investigator from the USDA, Paul D. Frenzen, entitled, “Deaths due to Unknown Foodborne Agents” (http://www.cdc.gov/ncidod/EID/vol10no9/03-0403.htm). Frenzen questioned Mead’s methodology for estimating total deaths due to foodborne illness. As the same methodology was also used to estimate the total of illnesses and hospitalizations, the questions Frenzen raised also apply to them.
    But, “Wait a minute,” you say. “Frenzen ONLY questioned the methodology for computing deaths due to unknown pathogens NOT the total of all deaths due to foodborne illness.” Not actually. Under the heading, “Food-Related Illness and Death from Unknown Pathogens,” the Mead study methodology is laid out succinctly. “To estimate food-related illness and death from unknown pathogens, we used symptom-based data to estimate the total number of acute gastrointestinal illnesses and then subtracted from this total the number of cases accounted for by known pathogens; this difference represents the illness due to acute gastroenteritis of unknown etiology.”
    “Subtracted from” shows the total estimate of “acute gastrointestinal illnesses” was the starting point. Thus, Mead’s estimate for the total number of illnesses, hospitalizations and deaths due to foodborne illness was based upon estimates of acute gastroenteritis NOT based upon the FoodNet data as stated above. Thus, the Mead flow chart is very misleading.
    In addition, the timing and location of Frenzen’s critique is of great significance. It was published 5 years after Mead. Clearly, the editors of EID would not have published it had Mead been right and Frenzen wrong. Plus, like Mead, Frenzen’s article was peer reviewed; so, multiple experts considered it. In addition, as Frenzen questioned the basic methodology of Mead and it would be very widely read within the food safety and even broader medical community by lots of people with strong scientific reasoning skills, I have no question, the peer review was extensive and careful.
    Finally, by printing Frenzen’s critique of Mead in the same journal, “Emerging Infectious Disease,” published by the CDC, the editors were saying Frenzen SUPERCEEDS some of Mead. That is how science works.
    Also, on 4-20-10, Caroline Smith DeWaal told me by phone that a “new CDC estimate” is in “peer review.” Hmm. Seven months of peer review. Thus, it is inaccurate and misleading to quote the Mead estimates as if they were the current estimates of the CDC.
    But the apologists for S 510/HR 2749 don’t stop there. A “CDC estimate” isn’t good enough.
    Rather, most do as Sen. Richard Durbin (D-IL)—the original sponsor of S 510—did on September 23rd on the floor of the Senate in his debate with Sen. Tom Coburn, MD (R-OK). Durbin said, “The cost of doing nothing can also be measured in lost quality of life. Each year, 76 million Americans suffer from a preventable foodborne illness. For some of them, it is an upset stomach or diarrhea, but for others it is more; 325,000 people are hospitalized, accumulating large medical bills, each year, and 5,000 people pay for food contamination with their lives. That is the reality of what they face.” The “CDC estimate” has now become actual illnesses, actual hospitalizations and actual deaths.
    Sen. Durbin, et al, those are over inflated estimates not actual diseases. Besides, tell me, how do we prevent almost 82% of them when your study says we don’t even know what pathogen causing the illness is? Quit deceiving the American people as to the actual extent of foodborne illness and its resulting hospitalizations and deaths.
    Bill, I hope you will set an example for improving the honesty of the food safety debate by making certain that neither you nor any of those working for Marler Clark or its publications cite the information in the Mead study misleadingly. Furthermore, I hope you and your publications will push the CDC to publish new estimates as it should have within a year or so of publishing Frenzen in 2004.

  • Harry, I really do not get why it seems that believers in small, local or raw have so much venom? I think they need to eat some processed food and relax just a bit(e), it might actually help having a sane conversation.
    I guess you still do not like S. 510 – even with Tester/Hagan in it? Compromise is part of Democracy. “Love it, or leave it.”
    It will be interesting to see what happens Monday. Your hero, Senator Coburn, is all set to complain about the cost of the bill (certainly wish he had those same concerns with the 2001 Bush tax cuts and NOT funding two wars). I think S. 510 has a 60% chance of passing and I think there is a 30% chance the House will compromise it with HB 2749 and a 5% chance the President will get to sign it. After that, a discussion of food safety is “toast.” The R’s will never bring it up – like they never did when they were in control before. So, you should feel confident that your world will not collapse.
    Several of the authors of the Mead study did come from the CDC. The CDC has cited those numbers for decades, as have the media. I do find it interesting that the Mead numbers (76M, 325K, 5K) have been cited for years as real numbers when Mead made clear the limitations. I am looking into how it became common wisdom – like the belief that local food is safer.
    I think having more accurate numbers of ill and estimates would be great, and I look forward to them next year – from the CDC. However, your comment – would “the apologists for the S 510/HR 2749 approach to regulating food safety quit misusing and abusing the out-of-date, 1999 Mead study” assumes that the numbers have mattered. Tell me Harry, where was the rush to “fix” food safety in 1999, 2000, 2001, etc? The reality is that the Mead numbers were only a part of the rationale for the food safety push in 2006. High profile monthly outbreaks and thousands of illnesses likely had a much greater impact that numbers published several years earlier.
    You may feel that people who are trying to move food safety forward have some evil intent. Some might. I simply am tired of seeing sick kids and am trying to help fix a food system that from my perspective is broken.

  • Bill, I’ll be happy to address the issues you have raised in your reply AFTER you address the issues I have raised.
    Until then, I will only address the issue raised in your second to last paragraph (“However, your comment – would ‘the apologists for the S 510/HR 2749 approach to regulating food safety quit misusing and abusing the out-of-date, 1999 Mead study’ assumes that the numbers have mattered.”) by referring you to the quote from Durbin on 9-23-10 on the Senate floor in my third to last paragraph.
    If the numbers haven’t mattered, Bill, why do Durbin and proponent after proponent quote them usually wrongly? And, Bill, have you used the numbers in your advocacy of S 510/HR 2749, et al?
    And, Bill, since my earlier comment I’ve realized your statement, “In 1999 the CDC using FoodNet estimated that foodborne diseases caused approximately 76 million illnesses, 325,000 hospitalizations, and 5,000 deaths in the United States each year,” is NOT CORRECT.
    Please re-read the 6 paragraphs of Mead just below Table 3. They are entitled, “Food-related Illness and Death from Unknown Pathogens” and “Total Cases.”
    The estimates in the famous quote were deduced ONLY from Mead’s estimate of the amount of acute gastroenteritis NOT from the FoodNet statistics. That is of paramount importance. I had to read Mead and analyze it many times before I realized what had actually occurred. Mead is so far from transparent that I now question whether or not it might have been artfully written to obscure that or the “experts” didn’t realize it themselves.
    In either case, the result has been a fundamental misunderstanding of the Mead study.

  • New estimates out at 2 today