The 2021–2025 Yu Shang Ready-to-Eat Meat–Listeria Outbreak: Three Years of Silent Contamination

At a glance

Detail	Fact
Product	Ready-to-eat meat and poultry (Yu Shang Food, Inc.)
Hazard	Listeria monocytogenes
Year	2021–2025 (recall 2024)
Scale	24 confirmed illnesses in 9 states; 22 hospitalized; 3 deaths
Outcome	Expanded recall of 72,240 pounds; outbreak strain found in plant product during routine FSIS testing

What happened

The samples told a story spanning more than three years. When CDC investigators assembled the Listeria isolates in the Yu Shang outbreak, the collection dates ran from October 24, 2021, to January 25, 2025 — a persistent, low-level contamination event at a ready-to-eat meat and poultry producer that sickened people for years before it was recognized. Twenty-four people across nine states were confirmed ill. Twenty-two were hospitalized. Three died — and all three deaths were infants.

The human toll of this outbreak is among the most devastating in this collection, and it fell overwhelmingly on pregnancies. Eight of the illnesses were related to pregnancy. In California, a mother and her twins fell ill; both infants died. (Listeria was confirmed in samples from the mother and one twin but not the other, so only the mother and one twin were counted among the confirmed cases.) In Tennessee, a mother and her infant fell ill, and the infant died. One pregnant woman fell ill and recovered; other infants were sickened and survived. The patient age range — from less than one year to 91 — and the fact that all of the patients were Asian pointed to a product with a specific cultural consumer base: Yu Shang’s ready-to-eat meats, the kind of products bought at Asian grocery stores and eaten without further cooking.

The breakthrough came from routine testing, not from epidemiology. On October 21, 2024, FSIS conducted routine sampling at the company’s facility and confirmed that a pork snout product was contaminated with Listeria monocytogenes — and whole-genome sequencing showed the pathogen was closely related to bacteria from sick people. The plant was the source, proven by the product. Yu Shang recalled ready-to-eat meat and poultry products on November 9, 2024, then expanded the recall on November 21 to 72,240 pounds after a second strain was identified in additional sampling. The recall covered all products produced before October 28, 2024.

The three-year duration points to the same conclusion seen in other persistent Listeria outbreaks: an entrenched environmental reservoir at the production facility, seeding product intermittently over years. Listeria biofilms in drains, on equipment, in hard-to-clean niches — surviving sanitation, recontaminating product, invisible until someone gets sick. For more than three years, that cycle repeated.

The outbreak ended on March 13, 2025, with 24 confirmed cases, 22 hospitalizations, and 3 deaths. But the confirmed count almost certainly understates the true toll. Listeriosis in pregnancy can cause miscarriage and stillbirth that are never linked to food; infant deaths from Listeria may be attributed to other causes. The three confirmed infant deaths are the visible edge of a larger harm.

Outbreaks concentrated in specific cultural communities demand communication strategies built for those communities. All of the Yu Shang patients were Asian, reflecting the product’s consumer base — shoppers at Asian grocery stores buying familiar ready-to-eat meats. Generic English-language press releases and mainstream media coverage may never reach these consumers. Effective outreach means multilingual notices, placement in the ethnic media and retail channels the community actually uses, and engagement with community organizations. A recall that does not reach its actual consumers is a recall in name only, and the Yu Shang outbreak is a reminder to map the consumer base before the crisis, not during it.

Timeline

• October 24, 2021–January 25, 2025: Twenty-four listeriosis cases with related strains occur across 9 states, unrecognized as a single outbreak.
• October 21, 2024: Routine FSIS testing at Yu Shang’s facility finds Listeria monocytogenes in a pork snout product, closely related to patient isolates.
• November 9, 2024: Yu Shang recalls ready-to-eat meat and poultry products.
• November 21, 2024: Recall expanded to 72,240 pounds after a second strain is identified; all products produced before October 28, 2024, covered.
• March 13, 2025: CDC declares the outbreak over: 24 cases, 22 hospitalizations, 3 deaths.

Root cause

Routine FSIS testing recovered Listeria monocytogenes closely related to the outbreak strains from Yu Shang product at the company’s facility, confirming the plant as the source. The three-plus-year span of illnesses indicated persistent environmental contamination — harborage sites seeding product intermittently — rather than a single contamination event. A second strain identified during the investigation expanded both the case count and the recall.

Regulatory and business outcome

Yu Shang’s recall expanded to 72,240 pounds covering all products produced before October 28, 2024. The outbreak’s devastating pregnancy outcomes — three infant deaths — made it one of the most consequential Listeria events of recent years and intensified scrutiny of Listeria control in small ready-to-eat meat processors serving specialty markets.

Lessons for food safety professionals

1. Multi-year outbreaks mean environmental harborage. Illnesses spanning 2021 to 2025 are the signature of biofilm entrenched in the plant. When cases stretch across years, stop looking for a bad lot and start looking for a bad drain.

1. Routine regulatory testing solves outbreaks. The plant link came from FSIS’s ordinary sampling program, not from epidemiology. Support robust routine testing — it finds what investigations cannot.

1. Specialty markets need targeted outreach. All patients were Asian, reflecting the product’s consumer base. Outbreak communications must reach the actual consumers — in their languages, through their media and retail channels.

1. Pregnancy-related listeriosis is undercounted. Miscarriages and stillbirths caused by Listeria often go unattributed. Treat every pregnancy-associated case as a signal of wider harm, and communicate the risk explicitly to prenatal care providers.

1. Second strains expand investigations. The additional strain found during this investigation grew both the case count and the recall. Keep looking after the first match — Listeria harborage often involves multiple strains.

1. Small processors need the same Listeria rigor as large ones. Yu Shang was not a industry giant, but its products reached nine states. Scale of distribution, not scale of company, should determine the intensity of environmental controls.

Sources

• “Listeria Outbreak Linked to Ready-to-Eat Meat and Poultry Products,” Centers for Disease Control and Prevention, 2025. http://cdc.gov/listeria/outbreaks/meat-and-poultry-products-11-24/
• “Deadly Yu Shang Listeria Outbreak Ends With 24 Sick, 3 Dead,” Food Poisoning Bulletin, 2025. https://foodpoisoningbulletin.com/2025/deadly-yu-shang-listeria-outbreak-ends-with-24-sick-3-dead/