New regulations from the U.S. Department of Agriculture Food Safety and Inspection Service to be implemented in July mean broiler chickens produced in the U.S. will be subject to new performance standards for salmonella and a performance standard for campylobacter for the first time.
Inaccurate estimates of impact on foodborne illness
USDA-FSIS has estimated that, once the new standard is in place for two years, 39,000 illnesses due to campylobacter and 26,000 illnesses due to salmonellawill be eliminated. This conflicts with currently available data regarding human foodborne illness due to salmonella that Centers for Disease Control and Prevention reports, which show illness flat lining for the last 20 years.
If consumption of poultry were contributing to the prevalence of salmonellosis, then changes in prevalence in fresh poultry would be reflected in changes in human salmonellosis. This relationship has not been established. In fact, salmonella prevalence in chicken increased from 2000-2005 and decreased dramatically from 2005-2010, but no significant changes in human salmonellosis occurred. This clearly indicates that consumption of poultry is not having a significant impact on salmonellosis in humans.
The question is: If the industry spends millions, if not billions, of dollars meeting these new requirements, what impact will it have on human salmonellosis? Is it worth it? Were the billion dollars spent to implement the Hazard Analysis and Critical Control Point Final Rule/Salmonella Performance Standard worth it? What effect did it have on human salmonellosis? There needs to be government accountability for arbitrary implementation of regulation without any, and in some cases contradictory, evidence that the new regulation will have an impact.
Missing factors in regulatory policy
The new Salmonella Performance Standard fails to take into account two important considerations: variables outside of the control of the poultry industry that impact salmonella prevalence and the law of diminishing returns in efforts to reduce pathogens.
Variables outside industry control. Seasonality, humidity and disease conditions all significantly impact salmonella prevalence on poultry. These factors cannot be controlled by the industry. Studies have demonstrated that salmonellaprevalence varies by season. Moreover, articles have detailed how higher relative humidity in poultry houses can increase prevalence. A paper in Poultry Science (Russell, 2003) detailed how air sacculitis infections increase campylobacter counts on broilers. Another popular article with data from more than five million chickens showed that salmonella prevalence was significantly higher on birds with air sacculitis as well. Unfortunately, the FDA decided to ban the use of the only antibiotic (Enrofloxacin) that is effective for treating air sacculitis (as shown in a study by the Poultry Diagnostic Research Center at the University of Georgia).
With these variables, a poultry processing plant may be using a particular set of interventions day in and day out with great success, but if the temperature, humidity or disease outlook changes, it may not be able to meet the standard. How can the growers affect the weather? How can they control diseases when their only effective tools have been taken away?
Law of diminishing returns. There is a tenet in food microbiology that when disinfecting a food item, much more effort is required to eliminate the last few organisms than is required to eliminate large numbers of bacteria. In fact, 90% of the effort is required to eliminate the last 10% of bacteria. This is because the first 99% are low-hanging fruit. These are bacteria that are not encased in biofilms, loosely attached and in a location where the chemical can reach them. The remaining few organisms are firmly attached, encased in biofilms and cannot be disinfected easily.
The USDA-FSIS, by making the standard <7.5% is essentially saying that they want 92.5% of the chickens to have zero salmonella. Stated another way, USDA-FSIS is saying that it wants the industry to eliminate the last few remaining salmonella cells on many more chickens than was required previously. This is a tall order as these cells are firmly attached and require much more effort to eliminate.
USDA-FSIS may be expecting the industry to turn some knobs and make adjustments in response to the new the regulation that will make the prevalence go down further. The reality is that the industry will have a very hard time eliminating those last few salmonella cells that are making some of the chickens positive for salmonella.
Campylobacter performance standards
A campylobacter standard puts the poultry industry in a very difficult position. Currently, there is no intervention method that has been demonstrated to be consistently effective for eliminating campylobacter in chickens during grow-out.
Interventions used to control salmonellatransmission from breeder to baby chick (vaccination and hatchery intervention) and to prevent colonization of baby chicks (vaccination and competitive exclusion) have proven ineffective for campylobacter. In fact, the scientific community is still divided on whether campylobacter is vertically transmitted.
If it is not fully understood how the campylobacter organism is colonizing baby chicks, how can the industry implement effective interventions? This means the industry is left with no tools for controlling campylobacter in broiler populations, and all interventions must be implemented at the plant level. As with grow-out, no scientific studies exist that demonstrate that one particular intervention works well for controlling campylobacter.
Testing for campylobacter is costly
The reason why campylobacter has been getting attention over the last 10 years has nothing to do with this organism being an “emerged pathogen” as with E. coli O157:H7. Campylobacter was described back in 1886 by Theodor Escherich of Escherichia coli fame. This begs the question: Why are we focusing on it only now? The answer is because it is very hard to detect microbiologically and tools for detection have not been widely available.
Requiring the poultry industry to test for this organism will call for very specific and expensive CO2 incubators, specialized media, a phase contrast microscope, and personnel with far more microbiological training than most poultry companies currently employ to conduct the testing.
Sampling methods hamper U.S. industry competitiveness
There are other hidden costs involved with differences in sampling methods for foodborne pathogens between countries that impact trade. USDA requires a whole-carcass rinse to detect salmonella. In the EU, however, plant employees collect a 25-gram neck skin sample from three different carcasses and pool them.
In some other countries, the test method used is completely different (in particular for exported product) than the methods used regularly in the U.S. and EU. The chicken skin is sterilized using a blow-torch or iodine solution, then the skin is removed using sterile tweezers and a sample of deep breast muscle is taken and tested for salmonella. Not surprisingly, salmonella is never found using this technique, allowing companies and countries to state that they do not have any salmonella on their poultry. This is misleading and causes great confusion. By this testing method, a company could say that their chicken is sterile, which is, of course, ridiculous.
Meanwhile, the USDA-FSIS requires companies in the U.S. to post their salmonella prevalence, and their names, addresses and P-numbers on the Internet for the world to see, placing them at a competitive disadvantage. Efforts should be made by USDA-FSIS to standardize these testing methods.
High costs without measurable benefits
Scientific data exist that clearly demonstrate no relationship between human salmonellosis and prevalence of salmonella on poultry. The new performance standards will only place additional burdens on the poultry industry, possibly resulting in higher food costs to the consumer with no measurable public health benefit. Such significant changes, without strong scientific data showing public health benefits, place the U.S. chicken industry at a competitive disadvantage for export opportunities.
