Avian Leukosis: What is avian leukosis? Is avian leukosis a food safety concern?
In March of 2019, the National Chicken Council petitioned the U.S. Department of Agriculture’s Food Safety and Inspection Service (FSIS) to allow the removal of extremely rare lesions suspected to be caused by avian leukosis from the bird during processing and not require that the whole chicken to be discarded. This is because avian leukosis does not impact the whole chicken – it only impacts a specific part of the chicken. In July of 2020, FSIS granted the petition. FSIS published a proposed rule in the Federal Register and not until the public comment period is over and FSIS reviews and considers the comments could the rule become final.
Amending the current regulations is supported by scientifically sound rationales, including:
- Avian leukosis does not present a food-safety risk
- Modern understanding of the avian disease is much more advanced than when FSIS first developed its policy
- Leukosis is not a systemic disease
- Modern vaccination and breeding programs have all but eliminated avian leukosis
Below are some frequently asked questions and answers about avian leukosis.
What is avian leukosis?
Avian leukosis virus belongs to a family of viruses called “retroviruses.” The virus cannot spread to humans or any other species. Like all retroviruses, the virus is relatively weak and does not survive well outside of the bird. Avian leukosis impacts the bird’s immunity, and the virus can eventually form lesions in the internal organs of the bird such as the liver or spleen.
How often does avian leukosis occur?
According to FSIS data, avian leukosis is a “rare manifestation” in broiler chickens.1 According to the agency’s data from as early as 1984, avian leukosis was present in only 0.017 percent of young chickens slaughtered.2 That number is less than 0.001% today, or one-one thousandth of one percent.
Modern treatment, vaccinations, flock handling practices and biosecurity have effectively eliminated leukosis in commercial broiler and breeder operations. Nearly all birds are vaccinated against the causes of avian leukosis and its prevalence has been effectively eliminated from commercial flocks.
Is avian leukosis a food safety concern? Can it make someone sick?
USDA’s FSIS and other health agencies have recognized avian leukosis “is not transmissible to humans” and “does not present a human health concern,” a fact the agency has acknowledged since at least 1997.3 The viruses that cause leukosis are species-specific and cannot be transmitted to humans. The National Institutes of Health (NIH) has declared that neither virus “is associated with disease in healthy adult humans.”4 Comprehensive literature reviews of the viruses that cause leukosis have also concluded that neither disease presents any apparent risk to public health.5
In the rare occurrence avian leukosis is found on a chicken liver or spleen, are the other parts of the bird, like the breast or wings, affected?
No. In the small chance these lesions occur, they are easily found on the bird’s organs, such as the liver or the spleen, and the organs are discarded. The disease is local and not systemic, meaning it is confined to the organ and does not spread to other parts of the bird.
Considering these facts, NCC is requesting in our petition that the other parts of the bird – e.g. the breast meat, wings, drumsticks, etc. – not be thrown away because they are completely wholesome. In an effort to reduce food waste, we have an ethical obligation to use every part of the bird that is completely safe for human consumption.
Can avian leukosis be transmitted from birds to humans?
There is no scientific evidence to support the claim avian leukosis can be transmitted from birds to humans.
Does this mean USDA inspectors will no longer be inspecting chickens for avian leukosis?
There is and still will be FSIS inspectors on every production line inspecting each carcass after the carcass has been cleaned, inspected and trimmed, if necessary. Company employees are already trained to look for, and eliminate, lesions, bruises etc. on carcasses that are quality issues and pose no food safety concerns. The FSIS inspectors are the final check before the carcasses can move further through the process. By law, a plant cannot operate without FSIS inspectors present and inspecting each carcass before receiving the USDA seal for wholesomeness.
Do increased line speeds in poultry plants increase the risk of avian leukosis?
Company employees on the evisceration line are trained to look for and eliminate lesions, bruises, etc. on carcasses as they are quality issues and pose no food safety concerns. In the .0001% chance avian leukosis is present on a carcass, these employees are trained to identify it, no matter what speed the line is operating.
There are also FSIS inspectors on every production line inspecting every carcass after the carcass has been cleaned, inspected and trimmed, if necessary, by company employees. The FSIS inspectors are the final check before the carcasses can move further through the process. By law, a plant cannot operate without FSIS inspectors present and inspecting each carcass before receiving the USDA seal for wholesomeness.
Using current science and technology, companies have been safely operating evisceration lines of up to 175 birds per minute for more than two decades while producing safe, wholesome chicken.
For more information on poultry line speeds, please click here.
What are the benefits to consumers of the National Chicken Council’s petition?
The real benefit is that FSIS inspectors can spend less time focusing on rare quality issues, and more time on food safety issues, like Salmonella and other pathogens.