More babies have died in an outbreak of Listeria monocytogenes infections traced to Yu Shang Food Inc.’s ready-to-eat meat and poultry products.
In an outbreak update, the Centers for Disease Control and Prevention said 19 patients have now been identified and two infants have died in California and one in Tennessee. However, one of the babies in California – twins whose mother was also ill – did not test positive for the Listeria outbreak and is therefore not included in the outbreak total.
The patients are spread across eight states. Of the 17 patients for whom complete information was available, all 17 required hospitalization.
Seven of the diseases are related to pregnancy. One person who was pregnant and infected with the listeria outbreak recovered. Two sick babies who were infected also recovered.
Patients range in age from less than 1 to 86 years old.
State and local public health officials interview people about the foods they ate in the month before they got sick. Symptoms of a Listeria infection can develop within 70 days.
People reported buying their food from multiple stores. Of the 14 people interviewed, 11 people shopped in person and online at markets selling Yu Shang food products. Of the 13 people asked about pre-cooked chicken products, eight reported eating pre-cooked chicken products, and three specifically recalled eating Yu Shang brand pre-cooked chicken products.
Public health researchers use the PulseNet system to identify diseases that may be part of this outbreak. CDC PulseNet maintains a national database of DNA fingerprints of bacteria that cause foodborne illness. DNA fingerprinting is performed on bacteria using Whole genome sequencing (WGS). WGS showed that bacteria from the samples of sick people are genetically closely related. This suggests that people became sick from the same foods in this outbreak.
The actual number of sick people in this outbreak is likely higher than the reported number, and the outbreak may not be limited to states with known illnesses. This is because some people recover without medical care and are not tested for Listeria.
On October 21, the USDA’s Food Safety and Inspection Service (FSIS) conducted routine testing and follow-up activities of Yu Shang Food, Inc.’s finished product. Testing confirmed that the product was contaminated with Listeria. WGS showed that Listeria in pig snout products is closely related to bacteria from sick people. This means that people have probably gotten sick from eating food that Yu Shang Food, Inc. produced.
“In response to the investigation, FSIS collected additional samples of products produced at Yu Shang Foods, Inc. and from the production environment,” the CDC outbreak update said.
“The Listeria found in those samples was linked by WGS to the bacteria from eight other sick people in the PulseNet database and is different from the strain found in the pig snout sample and the eleven diseases already in the outbreak involved. These diseases were combined in one study.”
Yu Shang Inc. of Spartanburg, S.C., has recalled more than 72,000 pounds of products linked to the outbreak.
All Yu Shang ready-to-eat products produced before October 28 are subject to recall. For a list of affected products, click here. Product labels can be viewed by clicking here. The recalled products have location number “P-46684” or “EST. M46684” within the USDA inspection mark. These items have been shipped to stores nationwide and can be purchased online.
Consumers with questions about the recall can email ling16099@yahoo.com or contact Ling Li, factory manager of Yu Shang Food Inc., at 864-310-6313.
About Listeria infections
Food contaminated with Listeria monocytogenes may not look or smell putrid, but it can still cause serious and sometimes life-threatening infections. Anyone who has eaten recalled products and developed symptoms of a Listeria infection should seek medical attention and tell their doctor about possible Listeria exposure.
Also, anyone who has eaten any of the recalled products should monitor themselves for symptoms in the coming weeks, as symptoms of listeriosis can develop up to 70 days after exposure to Listeria.
Symptoms of a Listeria infection may include vomiting, nausea, persistent fever, muscle aches, severe headaches, and neck stiffness. Specific laboratory tests are needed to diagnose Listeria infections, which can mimic other diseases.
Pregnant women, the elderly, young children and people such as cancer patients with weakened immune systems are at particular risk of serious illness, life-threatening infections, other complications and death. Although infected pregnant women may experience only mild, flu-like symptoms, their infections can lead to preterm labor, infection of the newborn, or even stillbirth.
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