The U.S. Department of Agriculture’s Food Safety and Inspection Service (USDA-FSIS) investigated seven foodborne illness outbreaks potentially linked to FSIS-regulated products during Fiscal Year (FY) 2025, according to a newly released agency report. The investigations, conducted between October 1, 2024, and September 30, 2025, involved approximately 250 illnesses and 140 hospitalizations across multiple states.

Released alongside the outbreak summary, FSIS also published an after-action review describing how investigators eventually solved a multistate Listeria monocytogenes outbreak linked to ready-to-eat (RTE) meat and poultry products after initially closing the investigation without identifying a source.

FY 2025 Outbreaks Involved 250 Illnesses Across Multiple States

USDA-FSIS’ Applied Epidemiology Staff coordinated the seven FY 2025 investigations in collaboration with local, state, and federal public health partners. The U.S. Centers for Disease Control and Prevention (CDC) notified FSIS of five of the outbreaks, and all seven outbreaks involved illnesses in more than one state.

Among the outbreaks investigated in FY 2025, four were caused by L. monocytogenes (involving RTE meat/poultry, multi-ingredient, and multiple products), two by Escherichia coli O157:H7 (involving beef), and one by Salmonella Enteritidis (involving multi-ingredient products).

Products of interest included beef in two outbreaks, RTE meat and poultry products in one outbreak, and multi-ingredient foods in two outbreaks. Multiple products were investigated in two additional outbreaks.

In several investigations, FSIS initially examined products under its jurisdiction, but later evidence pointed to ingredients or foods regulated by the U.S. Food and Drug Administration (FDA) as the likely source of illness. For example, in the investigation of the McDonald’s E. coli outbreak in late 2024, ground beef was considered a potential vehicle at first, but was later ruled out. Onions, which are regulated by FDA, were ultimately identified as the likely source.

Recalls and Public Health Alerts

Of the seven outbreak investigations, three resulted in recalls by FSIS-inspected establishments. In one L. monocytogenes outbreak, FSIS reported both an initial recall and a Public Health Alert (PHA).

FSIS may request a recall when evidence indicates that distributed meat, poultry, or egg products are adulterated or misbranded and associated with human illness. PHAs may be issued when a product that posed a public health risk is no longer available in commerce, or when investigators cannot identify a specific implicated product.

Multi-Ingredient Foods Present Investigative Challenges

The report highlighted the complexity of outbreak investigations involving multi-ingredient foods, such as prepared pasta meals or home-delivered meal kits. These investigations often require coordination among multiple regulatory agencies to determine whether contamination originated from a specific ingredient or during final product production.

FSIS stated that rapid collaboration among federal, state, and local partners is essential for identifying contamination sources and preventing additional illnesses.

After-Action Report Describes Listeria Outbreak Linked to Yu Shang RTE Meats

In a separate after-action report released concurrently with the FY 2025 outbreak summary, FSIS detailed an investigation into a multistate L. monocytogenes outbreak linked to Yu Shang-brand RTE meat and poultry products.

The outbreak included 24 illnesses across nine states, resulting in 22 hospitalizations and three deaths.

Public health officials initially investigated illnesses that occurred between February and May 2024, but closed the investigation without identifying a source. Later in the year, however, a routine FSIS sample of an RTE seasoned pork snout product produced by Yu Shang Food Inc. tested positive for L. monocytogenes. Whole genome sequencing (WGS) analysis showed the isolate was closely related to clinical isolates from the earlier outbreak.

With this new evidence, FSIS, CDC, and state partners reopened the investigation. A Class I recall for the implicated product was issued on November 9, 2024.

During intensified sampling at the producing establishment and retail locations, investigators detected L. monocytogenes in additional environmental and product samples. These samples represented a second strain of the pathogen and were genetically linked by WGS to clinical isolates associated with another outbreak.

As a result, CDC combined the two outbreaks into a single investigation. The recall was subsequently expanded on November 21, 2024.

FSIS assessments at the facility identified several factors that may have contributed to contamination, including inadequate sanitation practices, insufficient separation between raw and RTE operations, and facility modifications that could have allowed cross-contamination.

Whole Genome Sequencing and Product Sampling Key to Solving Outbreak

According to FSIS, the investigation demonstrated the value of routine product and environmental sampling combined with WGS to identify outbreak sources and link illnesses to contaminated foods.

By comparing isolates from routine regulatory sampling with historical WGS data, investigators were able to connect the previously unsolved illnesses to a specific product and establishment.

FSIS noted that retail product sampling also played an important role in generating evidence during the investigation.