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Published August 2026

Salmonella Risk in the U.S. Poultry Industry: When Infections Become More Severe and Harder to Treat

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The U.S. poultry industry and federal regulators have, for years, pointed to decreasing salmonella contamination as evidence that efforts to control salmonella are progressing. Yet USDA reports that there has been no corresponding reduction in human illness. Although USDA emphasizes reductions in the overall level of salmonella in poultry products, its public messaging gives little attention to the specific salmonella strains that persist in the food supply—strains that increasingly include some of the most dangerous-to-humans and difficult-to-treat pathogens.

While Farm Forward’s first report on salmonella analyzed overall contamination rates in the poultry industry, and exposed the most contaminated slaughter and processing plants and the inability of the federal government to regulate salmonella contamination, our latest investigation focuses on the changes in salmonella strains in the poultry industry from 2014 to 2025 and the danger they represent. Using USDA Food Safety and Inspection Service (FSIS) surveillance data from poultry slaughter and processing plants, this report goes beyond basic contamination metrics to evaluate the factors that most directly influence human health risk: which salmonella serotypes (strains) are circulating in the industry, how likely they are to cause severe disease, and how difficult infections may be to treat.

The findings reveal a worsening risk profile for public health. In our new analysis of FSIS salmonella serotype and antibiotic resistance testing data, we found that, over the last decade, contamination with high-virulence and multidrug-resistant strains linked to invasive infection, hospitalization, and death has risen sharply and shows no indication of slowing or reversing. In other words, while the percentage of positive salmonella tests is lower overall, a growing share of the salmonella that exists is among the most dangerous to human health.

This shift reflects not only changes in the prevalence of individual serotypes, but also the broader conditions under which poultry is produced and processed. Features of intensive poultry production—including high-density housing, rapid processing speeds, genetic uniformity that weakens birds’ immune resilience, and repeated opportunities for transmission across the production system—can create conditions that favor the persistence and spread of certain high-risk serotypes. Since these serotypes rarely make the animals sick, they are the ones that are amplified and dominate over time. 

Our analysis found that these risks are not evenly distributed across the industry. Certain slaughter and processing plants owned by major poultry companies repeatedly emerge as centers of persistent contamination by highly virulent, antibiotic-resistant strains. This concentration challenges the argument that dangerous salmonella contamination is an unavoidable consequence of poultry production. Instead, it suggests that facility-level practices, supply-chain conditions, and regulatory oversight play an important role in determining whether high-risk pathogens persist and spread. As a result, responsibility for controlling salmonella risk cannot be placed primarily on consumers through food handling and cooking practices at home. 

The persistence of these contamination hotspots also raises questions about accountability. Some companies continued to operate facilities where dangerous salmonella strains recur year after year despite ongoing monitoring, while regulatory responses have done little to eliminate the risks posed by their infrastructure and practices. The result is a food-safety system that tolerates conditions reliably generating a measurable level of ongoing exposure to highly virulent and antibiotic-resistant strains. Our findings show how these risks have evolved over time and where they are most concentrated.

Key Findings

  • Dangerous serotypes have grown to dominate in the industry, now accounting for 67.9 percent of salmonella, with no sign that this shift is reversing. 
    • The serotypes most likely to cause human illness (Salmonella Infantis, Salmonella Enteritidis, and Salmonella Typhimurium) have grown much more common, increasing by 43.6 percentage points since 2014 and now accounting for more than two-thirds (67.9 percent) of salmonella in the industry in 2025, up from only one-quarter of samples (25.3 percent) in 2014.
    • The Infantis strain has increased significantly (from 5.4 percent in 2014 to 35.7 percent in 2025), concerning public health officials due to its prevalence, its link to serious illness, and its widespread resistance to multiple antibiotics. 
  • Antibiotic resistance and multidrug resistance are on the rise, now accounting for 73.3 percent of positive poultry samples.
    • In 2025, roughly 73.3 percent of poultry samples that tested positive for salmonella were resistant to at least one antibiotic identified by the World Health Organization (WHO) as highly important for human medicine, an increase of 25.2 percentage points from 48.1 percent in 2014.
    • Multidrug resistance also showed a significant increase: 32.4 percent of positive tests were resistant to three or more antibiotic classes in 2025, up from 15.9 percent in 2014. Some poultry samples show resistance to up to 10 antibiotics. 
  • The serotypes most associated with human illness now carry high rates of resistance to one or more antibiotics. 
    • In 2014, only 3.2 percent of isolates of the dangerous Enteritidis strain were resistant to any antibiotics. By 2025, that had climbed dramatically to 70.6 percent of Enteritidis samples (a 67.4 percentage-point increase). In addition, 0.7 percent of positive samples were multidrug-resistant, up from 0.0 percent in 2014. 
    • 94.3 percent of Typhimurium isolates were resistant to one or more antibiotics in 2025 (a 13.1 percentage-point increase from 81.2 percent in 2014), and 46.5 percent of positive samples were multidrug resistant, a 26.5 percentage-point increase from 20 percent in 2014. 
    • 97.8 percent of Infantis isolates were resistant to one or more antibiotics in 2025, a 90 percent increase from 7.8 percent in 2014. 81.7 percent were multidrug resistant, a 75.8 percentage-point increase from 5.9 percent in 2014.
  • Top poultry companies showed some of the highest rates of high-virulence serotypes and antibiotic resistance. In 2025:
    • High-virulence serotypes accounted for more than 75 percent of samples at well over a dozen of the highest-risk poultry plants, including certain plants owned by Perdue, Butterball, and Pitman Farms. 
    • Plants showed alarmingly high contamination of birds by antibiotic-resistant salmonella. The worst Pitman and Butterball plants had an overall antibiotic resistance rate of more than 60 percent in positive samples, and over 90 percent of the positive samples at two of Perdue’s plants showed contamination with antibiotic-resistance serotypes. 
    • Multidrug resistance appeared in nearly one-fifth of positive tests at one of Butterball’s plants, more than a quarter of tests at Pitman’s plant, and more than one-third of tests at two of Perdue’s plants. 
    • Across all metrics (contamination rate, high-virulence rate, and antibiotic and multidrug resistance rates), these three companies have at least one processing plant whose samples ranked among the country’s top 25 highest-risk from 2014 to 2025.  

Our findings reveal that the industry’s problem is no longer just generic salmonella contamination. Increasingly, the strains dominating poultry production are among the most severe human pathogens and among the most difficult to treat when infection occurs. The persistence and continued growth of these strains suggest that the industry’s salmonella problem is becoming more dangerous, not less.

These dynamics point to a broader system in which production conditions, not only individual plant performance, determine the persistence and evolution of high-risk pathogens.

The consequences extend far beyond individual cases of food poisoning. Every year that multidrug-resistant salmonella circulates through poultry production systems, the industry erodes the effectiveness of antibiotics that remain critical for human medicine. The continued spread of these strains increases the risk not only of illness, hospitalization, and death from salmonella, but also of salmonella’s resistance spreading more broadly to other bacterial pathogens. The stakes of antibiotic resistance cannot be overstated: As bacteria develop resistance to antibiotics, treatment options narrow, leading rapidly to what the World Health Organization (WHO) has characterized as a post-antibiotic era, where many common injuries and illnesses that have been easily treated since the advent of antibiotics—a scraped knee, strep throat, a urinary tract infection, an ear infection—again become potentially life-threatening.

To assess the compounding risk emerging from the poultry industry, this report examines trends in high-virulence, antibiotic-resistant serotypes in poultry production, how the industry and current regulatory systems have failed to contain these dangerous pathogens, and which companies and facilities are driving some of the highest-risk contamination patterns.