Key Points:
Two people infected with the outbreak strain of Listeria have been reported, one from Michigan and one from Nevada. Both have been hospitalized, and no deaths have been reported.
The true number of sick people in this outbreak is likely higher than the number reported, and the outbreak may not be limited to the states with known illnesses.
This is because some people recover without medical care and are not tested for Listeria. In addition, recent illnesses may not yet be reported as it usually takes 3 to 4 weeks to determine if a sick person is part of an outbreak.
Interviews with sick people and laboratory findings show that enoki mushrooms contaminated with Listeria are making people sick.
Both sick people reported eating enoki mushrooms or eating at restaurants with menu items containing enoki mushrooms.
The outbreak strain was previously found in one sample of enoki mushrooms collected by FDA. However, to date, the firm associated with this sample has not been identified as a potential source of enoki mushrooms in this outbreak.
Investigators are working to identify specific brands of enoki mushrooms that may be contaminated with the outbreak strain of Listeria.
CDC previously investigated a Listeria outbreak linked to enoki mushrooms in 2020. Since then, FDA and public health officials from several states have been collecting samples of enoki mushrooms, resulting in more than 20 recalls of enoki mushrooms due to Listeria contamination.
What People At High Risk for Listeria Illness Should Do:
Listeria is especially harmful if you are pregnant, aged 65 or older, or have a weakened immune system due to certain medical conditions or treatments. If you are pregnant, it can cause pregnancy loss, premature birth, or a life-threatening infection in your newborn.
If you are pregnant, aged 65 or older, or have a weakened immune system: Do not eat raw enoki mushrooms. Cook enoki mushrooms thoroughly. Keep enoki mushrooms separate from foods that won’t be cooked. Wash your hands after handling raw enoki mushrooms, and clean your refrigerator, containers, and surfaces that touched raw enoki mushrooms.
Call your healthcare provider right away if you have any symptoms of severe Listeria illness after eating enoki mushrooms.
About Listeria:
Listeria can cause severe illness (known as invasive listeriosis) when the bacteria spread beyond the gut to other parts of the body. Almost all severe illnesses from Listeria result in hospitalizations and sometimes death.
Pregnant people and their newborns, adults 65 years or older, and people with weakened immune systems are at higher risk for severe illness. Other people can be infected with Listeria, but they usually get mild food poisoning symptoms, like diarrhea and fever, and usually recover without treatment.
Symptoms of severe illness usually start within 2 weeks after eating food contaminated with Listeria, but may start as early as the same day or as late as 10 weeks after.
People who are not pregnant may experience headache, stiff neck, confusion, loss of balance, and convulsions, in addition to fever and muscle aches.
Pregnant people usually experience only fever, fatigue, and muscle aches. However, Listeria can cause pregnancy loss or premature birth. It can also cause serious illness or death in newborns.