Officials with the Food and Drug administration are doubling down on their warning against certain enoki mushrooms because the Centers for Disease Control and Prevention have confirmed another patient in a Listeria outbreak.

The public warning issued Jan. 18 came on the heels of a Jan. 17 announcement that the FDA had determined that Utopia Foods brand enoki mushrooms are behind an outbreak caused by Listeria monocytogenes.

The Centers for Disease Control and Prevention and the Food and Drug Administration have been investigating the outbreak for several months. As of Jan. 18, the CDC is reporting sick people in California, Nevada and Michigan with each state having one confirmed patient with the outbreak strain. The outbreak strain has been confirmed on some mushrooms sold under the Utopia Foods brand.

All patients have required hospitalization. It is difficult to trace Listeria infections to implicated foods because it can take up to 70 days for symptoms of infection to occur.

Two patients reported eating enoki mushrooms before becoming sick. The third reported going to a store that specializes in Asian foods. Enoki mushrooms are long thin white mushrooms, usually sold in clusters. They are especially popular in East Asian cuisine and are also known as enokitake, golden needle, futu, seafood, or lily mushrooms.

There have been numerous recalls of imported enoki mushrooms sold under a variety of brand names in the past year because of Listeria contamination, but this is the first time a specific brand has been linked to illnesses. Listeriosis is a serious disease that develops from the pathogen Listeria monocytogenes and often results in death.

Utopis Foods Inc. of Glendale, NY, initiated a recall of some of its enoki mushrooms in late November and expanded that recall on Dec. 13. 

The recalled fresh imported mushrooms may still be in the possession of consumers because of their long shelf life. The initially recalled mushrooms had dates of “Best before 03/02/2023” or “Best before 03.09.23” The fresh mushrooms were distributed between Jan. 6, 2023, and Jan. 13, 2023, in New York, New Jersey, and Connecticut to wholesale companies for further distribution.

The mushrooms subject to the expanded recall were imported from China and shipped nationwide.

“Through ongoing sampling efforts, FDA and state partners have been collecting and testing samples of enoki mushrooms. An import sample of enoki mushrooms branded as Utopia Foods, Inc. was collected by FDA and was reported as being positive for Listeria monocytogenes. Whole Genome Sequencing (WGS) analysis determined that the strain of Listeria found in this sample matches the strain of Listeria linked to illnesses in this outbreak,” according to an update from the FDA.

“FDA’s investigation is ongoing to determine a potential source of contamination and whether any other products are contaminated or linked to illnesses. Additional information will be provided as it becomes available.”

The FDA and CDC are advising consumers, restaurants, and retailers to not eat, sell, or serve recalled enoki mushrooms from Utopia Foods Inc.

Public health officials say enoki mushrooms should always be cooked thoroughly to kill any foodborne germs.

Consumers, retailers and restaurants should follow FDA’s safe handling and cleaning advice and use extra vigilance in cleaning and sanitizing any surfaces and containers that may have come in contact with fresh enoki mushrooms to reduce the risk of cross-contamination, including retailers who stored or repackaged recalled enoki mushrooms. Listeria can survive in refrigerated temperatures and can easily spread to other foods and surfaces.

About Listeria infections
Food contaminated with Listeria monocytogenes may not look or smell spoiled but can still cause serious and sometimes life-threatening infections. Anyone who has eaten any enoki mushrooms and developed symptoms of Listeria infection should seek medical treatment and tell their doctors about the possible Listeria exposure.

Also, anyone who has eaten any of the recalled products should monitor themselves for symptoms during the coming weeks because it can take up to 70 days after exposure to Listeria for symptoms of listeriosis to develop. 

Symptoms of Listeria infection can include vomiting, nausea, persistent fever, muscle aches, severe headache, and neck stiffness. Specific laboratory tests are required to diagnose Listeria infections, which can mimic other illnesses. 

Pregnant women, the elderly, young children, and people such as cancer patients who have weakened immune systems are particularly at risk of serious illnesses, life-threatening infections, and other complications. Although infected pregnant women may experience only mild, flu-like symptoms, their infections can lead to premature delivery, infection of the newborn, or even stillbirth.