In November 2024, public health investigators announced a multistate outbreak of Listeria monocytogenes infections associated with ready-to-eat meat sold by Yu Shang Food. Two strains of Listeria were detected. As of December 5, 2024, 19 people from 8 states were infected with one of the outbreak strains of Listeria. Sick people's samples were collected from October 24, 2021 to October 28, 2024.

Of the 19 people with available information, 17 (89%) were hospitalized. Seven illnesses were related to pregnancies. One person who was pregnant was sick and recovered. Two unrelated infants were also sick and recovered. In California, a mother and her twins were sick and both infants died. Listeria was found in a sample from the mother and from one of the twin infants, but it could not be found in a sample from the other infant. Because of this, only the mother and one twin are included as confirmed cases in this outbreak. In Tennessee, a mother and her infant were sick and her infant died.

In interviews with public health officials, ill people reported buying foods from multiple stores. Among the 14 people interviewed, 11 people shopped in person and online at markets where Yu Shang food products were sold. Among the 13 people asked about precooked chicken products, eight (62%) people reported eating precooked chicken products, and three people (38%) specifically reported eating Yu Shang brand ready-to-eat chicken products.

On October 21, 2024, FSIS conducted routine testing and follow-up activities of finished product by Yu Shang Food, Inc. Testing confirmed that the product was contaminated with Listeria. WGS showed that the Listeria in pork snout product was closely related to bacteria from sick people.

In response to the investigation, FSIS collected additional samples of product produced at Yu Shang Foods, Inc. and from the production environment. The Listeria found in those samples was related by WGS to the bacteria from eight other sick people in the PulseNet database and is different from the strain found in the pork snout sample and the 11 illnesses already included in the outbreak. These illnesses were combined into one investigation.

On November 9, 2024, Yu Shang Food, Inc recalled ready-to-eat meat and poultry products. On November 21, 2024, Yu Shang Food, Inc expanded their recall. CDC is advising people not to eat, sell, or serve recalled products.