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Salmonella on Chicken: Is Zero Tolerance Feasible?

At the end of 2013, Consumer Reports made national headlines by reporting that 97 percent of retail chicken breasts were contaminated with some form of gut bacteria. Granted, not all of those bacteria are likely to make consumers sick, but the report did find potentially harmful Salmonella on 11 percent of the samples.

The story resonated especially well with readers who expressed frustration over the recent multi-state Foster Farms Salmonella outbreaks, which had together sickened more than 550 people and hospitalized nearly 200 in the latter half of 2013. In a similar survey funded by Food Safety News publisher Marler Clark in 2011, a microbiology laboratory found Salmonella on 19 out of 100 raw chicken samples purchased from grocery stores in the Seattle area.

The recent findings have prompted many in the food industry to discuss strategies for mitigating Salmonella on chicken. Some have begun searching for examples in the European Union, where some countries have reported marked reductions in contamination levels since declaring a “zero-tolerance” policy on Salmonella on chicken.

One proponent of a European-style zero-tolerance policy is Dr. Urvashi Rangan, toxicologist and executive director of the Consumer Reports Food Safety and Sustainability Center, who spoke with Food Safety News after the release of the Consumer Reports survey.

According to Rangan, Europe’s zero-tolerance policy for Salmonella on chicken has resulted in significantly lower levels of contamination in recent years, with some estimates putting Salmonella levels below 1 percent in countries such as Denmark and Sweden. By comparison, while Salmonella rates on poultry in the U.S. have dropped in recent years, they are still nowhere near the 1-percent benchmark across the Atlantic.

But would a zero-tolerance policy on Salmonella work in the U.S.? Some say we’ve already done it with E. coli in ground beef, while others argue that Salmonella in chicken is a completely different beast.

Proponents of a zero-tolerance policy cite the example of the U.S. Department of Agriculture’s decades-old zero-tolerance policy of E. coli O157:H7 in ground beef, which prompted largely successful efforts to curb contamination rates. Others, including some microbiologists and USDA officials, argue that zero tolerance cannot feasibly work on the scale and cost within which the U.S. food system operates.

Chicken, Apples and Oranges

More than 20 years ago, the U.S. witnessed the country’s first great foodborne illness outbreak when, in 1993, hundreds of people fell ill and four children died after eating Jack in the Box hamburgers contaminated with E. coli. A year later, the USDA’s Food Safety and Inspection Service (FSIS) declared E. coli an adulterant in ground beef, making it illegal to sell food contaminated with the bacteria.

In contrast, raw meat cannot be recalled or held from commerce for containing Salmonella. Some consumer advocacy groups are trying to change that, having petitioned USDA to begin considering some forms of Salmonella as adulterants.

Though the U.S. beef industry first challenged the USDA’s classification of E. coli as an adulterant, beef producers have since taken to the challenge of eradicating E. coli from beef supplies, seeing significant reductions in outbreaks and recalls in recent years. That progress is largely thanks to the government first mandating E. coli’s adulteration status, said Chris Waldrop, director of the Food Policy Institute at the Consumer Federation of America.

“I think declaring Salmonella an adulterant makes life easier for FSIS,” Waldrop said. “Making that sort of declaration provides them with an easier path to keeping contaminated food off the market instead of having to take an indirect route to address problems at plants.”

But declaring Salmonella an adulterant in chicken and effectively implementing a zero-tolerance policy is just not feasible on the scale at which the U.S. poultry industry operates, said Michael Doyle, microbiologist and director of the Center for Food Safety at the University of Georgia.

Comparing E. coli in beef to Salmonella in chicken – or even European poultry industries to the U.S. industry – is like comparing apples and oranges, said Doyle, whose research focuses on reducing the prevalence of pathogens carried on meat and poultry. Doyle is also on the science advisory board for Foster Farms.

Even the methods of measuring Salmonella prevalence cannot be trusted as equivalent between countries, he added. While Doyle agreed that at least some European countries likely had lower rates of Salmonella contamination on chicken, “but using the right methods, you’d likely find Salmonella in their products as well.”

And that’s not to consider the difference in scale between the industries in a European country and the U.S., he said.

“The Scandinavian countries probably produce as much chicken in a year as we do in a week in Augusta, Georgia,” Doyle said.

And pound-for-pound, chicken in countries that report less than a 1-percent contamination rate often costs three to five times that of U.S. chicken meat, he said.

Eliminate, or Just Reduce?

In wanting to reduce Salmonella contamination rates, Doyle said that some food safety advocates have altered the goal of “zero tolerance” from reduction to complete elimination, which he said just isn’t possible on raw chicken meat. The U.S. does, however, have a zero-tolerance policy for visible fecal contamination of chicken carcasses prior to entering the chiller at the processing facility.

In 2010, Doyle was part of a group of scientists from 16 countries who joined together to examine the scientific validity of “zero-tolerance” policies toward Salmonella on chicken. That group included scientists from Denmark, Sweden, and the Netherlands, as well as Asia, South America and New Zealand.

In a report, the group concluded that “there is neither an effective means of eliminating Salmonella from raw poultry nor any practical method for verifying its absence.”

Instead, the group recommended risk assessments and performance objectives linked to human health outcomes. In other words, setting goals of lowering contamination by removing risks, but ultimately accepting that Salmonella will never completely go away.

“You’re not going to be able to eliminate Salmonella from raw poultry,” Doyle told Food Safety News.

Zero tolerance isn’t feasible for any raw food in general, said USDA microbiologist Nelson Cox in an article written for Poultry World.

“Zero tolerance also implies that both minor and major deviations from a policy will be treated with the same severity,” Cox said. “This is obviously not a sensible approach to identifying and resolving the source of contamination problems.”

Ultimately, the biggest factors still come down to scale and cost. The U.S. simply produces chicken at too high of a volume to completely avoid Salmonella and still keep costs affordable, Doyle said. And the bottom line may determine it all.

“It’s virtually impossible to have zero Salmonella, according to the large-scale production conditions used here in the U.S., which help keep the price of poultry down,” Doyle said. “If you want chicken with no Salmonella, it’s going to cost a lot more money to produce.”

© Food Safety News
  • doc raymond

    Good piece, James. I have a couple of other thoughts to add to your discussion. While hundreds were sickened during the recent Salmonella outbreak, during that time frame the poultry associations estimate that Americans were eating 160 MILLION servings of poultry on a daily basis. Secondly, cooking an intact chicken breast in normal fashion will kill bacteria on its surface, with ground beef you have blended the E coli into the center of the patty making killing it more problematic. Of course there is always cross contamination from a chicken breast to deal with.

    • Carl Custer

      In some ways we are getting better; in others just
      holding steady. See the CDC charts at: http://www.cdc.gov/foodnet/data/trends/tables/table2a-b.html#table-2b
      Yes, millions of consumers prepare raw meat and poultry daily without negative health consequences. I believe those successes can be attributed to: (1) the low level of pathogens in and on raw meat and poultry, (2) the lower level of virulent pathogens, (3) the partial reduction in the level of pathogens even by undercooking, (4) the dilution of the level of pathogens during cross-contamination, (5) the human immune system that can defeat low levels of pathogens, and (6) luck.

  • John Munsell

    The admission made by USDA microbiologist Nelson Cox is erudite, and worth an article all its own. He stated above “Zero tolerance also implies that both minor and major deviations from a policy will be treated with the same severity. This is obviously not a sensible approach to identifying and resolving the SOURCE (emphasis mine) of contamination problems”. Yes, we do need some kind of standards, once we have the courage to admit that zero tolerance for salmonella in poultry is simply not achievable. FSIS can make all the pious posturings it wants about zero tolerance for salmonella, but there is always a place, indeed a need, for truth. So, what percent incidence of salmonella will be acceptable? Maybe 10% positives? Or 30% positives? If FSIS tenaciously adheres to a zero tolerance standard, then a plant with one half of one percent positives will face the same agency regulatory fury as a plant with 30 percent positives. Reason must prevail somewhere here. Nelson Cox also referred to the SOURCE of contamination problems, an issue which FSIS adroitly avoids. The source of Salmonella is animal intestines, as well as manure-covered feathers which carry intestinal residue. Therefore, salmonella arrives in and on live chickens as they arrive at the slaughter plant. Sloppy sanitary dressing procedures on the kill floor transfer Salmonella onto the carcass, and into the food supply. While Salmonella can be subsequently introduced into the food supply downstream, at a retail market or restaurant as examples, the vast majority is introduced at the source originating slaughter facility. We also must remember that HACCP was developed by Pillsbury over 50 years ago for fully-cooked, ready-to-eat foods guaranteed safe for astronaut use and in military battlefield rations where cooking facilities are not available. Thus, true HACCP was not designed for raw poultry. While HACCP concepts are still useful for raw poultry, FSIS-style HACCP must make accomodations for the presence of salmonella in poultry, which unfortunately is somewhat ubiquitous. We must also acknowledge that the judge in the Supreme Beef case did not throw out Salmonella Performance Standards, but he spanked a childish FSIS which attempted to place blame for Salmonella on the grinding plant (Supreme Beef), while totally ignoring the SOURCE of contamination, which was the slaughter plant(s) which sold Salmonella-laced trimmings to Supreme Beef. Tom Billy represented the agency at the trial, and foolishly claimed that the plethora of salmonella positives at Supreme Beef proved that the plant was unsanitary. To its disgrace, historical agency records at Supreme Beef did NOT reveal sanitation problems at Supreme Beef. Thus, Tom Billy utilized specious rationale to claim that adverse lab reports prove the existence of sanitation problems at a grinding plant, all the while intentionally ignoring the SOURCE of contamination, which USDA microbiologist Nelson Cox addressed in his comments above. FSIS has yet to learn from its well-deserved legal spanking. The incidence/prevalence of Salmonella is much larger than the incidence of E.coli, making the eradication of Salmonella that much more difficult. Furthermore, the infective dose in E.coli is much smaller than the infective dose in Salmonella, making E.coli much more lethal, thus more deserving of close FSIS scrutiny and enforcement actions. Perhaps Nelson Cox could train his USDA/FSIS superiors of the need to (1) trace back to the SOURCE, and (2) force the source to clean up its act. Don’t hold your breath. John Munsell

  • John Kall

    One thing I did not see in your report is
    that egg producers will feed their chickens egg shells from the eggs they just
    laid. Not sure though if a chicken with Salmonella can transmit it back to the
    new eggs.

  • Keith Warriner

    Introducing vaccinations at the farm level would be a start. Also introducing technologies such as ozone at the air chilling stage has proven effective against Salmonella. We can talk about new approaches but the industry has to be willing to accept them.

  • William James

    A couple of thoughts. (1) STECs are adulterants in non-intact beef products and their components. So, an analogous Salmonella standard in chicken would parallel this approach. (2) Only E. coli that causes food borne illness has a zero tolerance. Again, an analogous Salmonella standard in chicken would use this strategy.

    • Carl Custer

      Yessss. Not all salmonellae are pathogenic to humans. Those salmonellae pathogenic to economically important animals are controlled by APHIS and economic incentives. Salmonellae in raw meat or poultry that are pathogenic to humans are . . . well . . .”Just cook it”. I have a recommendation in the seventh article based on the Acts and current FSIS policy.

  • John Munsell

    Meat man, I agree with you! Irradiation should be pursued, and consumers can then chose between irradiated and non-irradiated meat. And if consumers blacklist irradiated meats, then we’re right back to where we are now with limited interventions for ubiquitous bugs like Salmonella. Assignment of blame is an uncomfortable issue, yet it is vital we put it out on the table. Plants CANNOT accomplish zero tolerance for Salmonella because of its high incidence in poultry. Fully cooking accomplishes zero tolerance, but consumers want to buy raw poultry and cook it themselves at home or at the restaurant. FSIS must establish microbial monitoring guidelines, to determine if a plant’s food safety record (aka testing records) falls within acceptable ranges. And perhaps the stringency of these guidelines should be slowly increased every year, to require continued improvement, which should be possible if we continue to implement new interventions and procedures. But how will the legal industry view this “shared” responsibility? Thus far, the meat industry has been held fully liable, which insulates the end user from any food safety requirements. Why do we even use Safe Handling Labels if we’ve pre-determined that the end user is not required to implement those safe handling protocols? I don’t have the answer to this legal accountability dilemma, but we’ve got to address it. John Munsell

  • tokies

    this wouldnt be an issue really. if we where not dealing with e-coli that is crazy. feed lot crap. same for the chicken . you could have got sick from a much weaker strain.