Preparation, storage of morels likely cause of illnesses at Bozeman restaurant

An investigation into what killed two people and left more than 50 others sick who ate at Dave’s Sushi in Bozeman earlier this year found morel mushrooms, and possibly their storage and preparation, were the likely causes of the illnesses, according to a report released Wednesday.

The Montana Department of Health and Human Services and Gallatin City-County Health Department released their findings from the investigation on Tuesday into why the people got sick after eating at the popular Bozeman restaurant between March 28 and April 17. The restaurant was ordered to close on April 20.

Two people died after eating there and three others were hospitalized out of more than four dozen people aged 18 to 74 who experienced symptoms including diarrhea, nausea, vomiting and abdominal pain, according to the health departments.

The two departments said in Wednesday’s report that morel mushrooms were “strongly associated” with people who developed gastrointestinal issues after eating at the restaurant over that time period – and that those who ate sushi with a greater quantity of the mushroom were more likely to have become ill.

The investigation could not determine exactly what in the mushrooms caused the outbreak, noting possible differences in how the mushrooms were stored after preparation on two dates in April, and that testing could not confirm the specific toxin that made people sick.

“However, the signs and symptoms of illness reported were consistent with what could result from eating morel mushrooms that were not properly handled, prepared, or cooked,” the two departments wrote in their report. “… Based on the strong epidemiological data, morel mushrooms were the most likely cause of the outbreak but there may be other contributing factors that were not identified during the investigation and that remain unknown.”

The departments interviewed 63 people who ate at the restaurant over the three-week span and found 41 of them got sick. The departments then compared what they ate with the orders of people who did not get sick and worked with the Centers for Disease Control and Prevention to study the data. They also worked with the U.S Food and Drug Administration to test the morels and other food samples.

Their analysis did not find any significant pesticides, heavy metals, bacteria or other pathogens, the departments said Wednesday. And the FDA traced the morels to restaurants in other states that had bought them from the same supplier – Dave’s Sushi said they came from a “reputable” California distributor – and found no illness among their customers. The departments said there were six other restaurants who had bought the mushrooms, and all of them cooked them before serving.

But the departments found that Dave’s Sushi marinated their mushrooms in a sauce that had just been boiled on April 8, and on April 17, the mushrooms were marinated in a sauce that had not been boiled before being served.

“Consumption of morels on both dates was associated with developing illness,” the report says. “However, consumption of morels was more strongly associated with developing illness on April 17, when the morels were reportedly prepared without any cooking process. Most individuals with severe outcomes dined at the restaurant on April 17.”

Both DPPHS and the Gallatin health department said there is still a lack of understanding about morel toxins but that cooking the mushrooms often helps reduce the risk of illness.

The Gallatin City-County Health Department has been regularly inspecting Dave’s Sushi and said the restaurant has been cooperative. The restaurant reopened on May 25 after getting approval from the health department, saying at the time those who got sick or died “remain in our hearts and will not be forgotten.”

The Bozeman Daily Chronicle reported that four lawsuits have been filed because of the illnesses, including wrongful death suits from families of the two people who died.

Dave’s Sushi provided the Daily Montanan with the following statement after the release of the report, saying it would no longer serve morel mushrooms and offering condolences to the families of those who died:

“We first want to acknowledge the Ventura and Lewis families and the passing of their loved ones. This is an unthinkable tragedy. We hope that no other families, friends and communities will experience the loss of someone they love as a result of eating morel mushrooms.

“We are thankful that the latest report has brought awareness about the dangers of morels. Due to this tragic situation, the FDA has shared on their website, updated as of today, July 19, 2023, ‘Consumers should eat morel and other wild-type mushrooms at their own risk. Properly preparing and cooking morel mushrooms can reduce risk of illness, however there is no guarantee of safety even if cooking steps are taken prior to consumption.’

“As a result of the unknowns and uncertainties, we will never serve morel mushrooms again.”