A recent investigation in Montana has determined that raw morel mushrooms served at a sushi restaurant were the most likely cause behind an outbreak that sickened over 50 people and resulted in two deaths.
The outbreak, which occurred between March and April of this year, affected individuals who consumed morel mushrooms at the restaurant. Those who consumed a greater quantity of sushi containing morels were more likely to develop gastrointestinal illness.
Health officials performed DNA sequencing on the morel mushroom samples and identified the species as Morchella sextelata.
Restaurants in other states that received morel mushrooms from the same supplier cooked them thoroughly and did not receive any reports of illnesses.
Health officials conducted DNA sequencing on the morel mushroom samples collected from the restaurant and confirmed the species as Morchella sextelata.
The investigation revealed that the morel mushrooms served at the restaurant were either raw or lightly cooked, depending on the date of preparation.
Owners of the sushi restaurant reported that morels served on April 8 underwent some light cooking by being marinated in a sauce immediately after the sauce had been boiled. However, morels served on April 17 were not cooked.
Restaurants in other states that received morel mushrooms from the same supplier cooked the morels thoroughly and did not experience any related illnesses.
The investigation had limitations in determining the specific characteristics of the morel mushrooms that caused the illnesses.
Public health officials recommend caution when consuming, selling, or serving morel mushrooms, as poisonous species can resemble them.
It is important to confirm the identity of each mushroom and consult with a knowledgeable expert to avoid potential risks.
Proper storage of morel mushrooms in breathable packaging and refrigeration at the appropriate temperature are also essential precautions.
Thorough cooking of morel mushrooms is likely to reduce toxin levels and minimize the risk of illness.
Individuals who experience symptoms after consuming morels should seek medical assistance.