A recent study has revealed that the majority of salmonella outbreaks linked to poultry are caused by a small number of specific strains. Despite there being over 2,600 different types of salmonella bacteria, researchers found that only three strains are predominantly responsible for illnesses in humans.
Interestingly, one of the most common salmonella types found in U.S. chicken, Salmonella Kentucky, accounts for less than 1% of human illness cases. In contrast, the strains Enteritidis, Infantis, and Typhimurium were responsible for 69% to 83% of these illnesses. This significant finding was reported in the Journal of Food Protection.
The study’s results support the U.S. Department of Agriculture’s (USDA) new approach to focusing its tracking and detection efforts on the most harmful salmonella strains. Matt Stasiewicz, an associate professor of food science and human nutrition at the University of Illinois Urbana-Champaign, emphasized the importance of this shift. “Over the last 20 years, the poultry industry has significantly reduced the frequency of salmonella in poultry,” Stasiewicz noted. “However, the number of people falling ill from these pathogens hasn’t decreased.”
Stasiewicz added that the USDA is considering regulatory changes based on the level and serotype of salmonella, which aligns with the study’s findings. According to the U.S. Centers for Disease Control and Prevention, salmonella bacteria cause approximately 1.3 million infections, 26,500 hospitalizations, and 420 deaths in the United States each year.
The Healthy People 2030 initiative aims to reduce salmonella infections to fewer than 11.5 cases per 100,000 people annually. To achieve this goal, the number of illnesses must decrease by 25% by the end of the decade. Analysis of USDA data indicated there are about two salmonella cases for every 1 million servings of chicken consumed in the U.S.
The study also found that the risk of salmonella poisoning is concentrated in a few chicken products carrying high levels of the most infectious strains. The next step for researchers is to develop strategies to specifically target these dangerous salmonella strains. Potential approaches include using statistical methods to monitor salmonella cases in poultry processing, holding batches of poultry products until thorough testing is completed, or vaccinating chickens against the worst strains.
“These findings support the USDA’s initiative to shift regulation towards high-level, high-risk contamination events rather than the frequency of detection,” Stasiewicz said. He hopes consumers will understand that this strategy is designed to protect public health. Stasiewicz explained that while it might seem like the new regulations are lenient on the industry by targeting specific pathogens, it is a logical approach to focus on the strains that are actually causing illnesses.
By honing in on the most dangerous salmonella strains, the USDA aims to improve public health outcomes and reduce the incidence of foodborne illnesses linked to poultry.
