On the 19th of July, 2023, the Montana Department of Public Health and Human Services (MT DPHHS) published the final report on the fatal Dave’s Sushi Morel Mushroom outbreak; of which caused over 50 illnesses, 3 hospitalizations, and 2 deaths. These individuals all dined at the Bozeman, Montana restaurant, Dave’s Sushi, between the dates of March 28th and April 27th, 2023.
The Montana Department of Public Health and Human Safety (MT DPHHS) and the Gallatin City-County Health Department (GCCHD) collaborated with the United States Food & Drug Administration (FDA) to perform food tests on samples of morel mushrooms; collecting DNA sequencing data, as well as proof of the presence of bacterial toxins, pesticides, heavy metals and pathogens. The tested samples of morel mushrooms revealed the species to be Morchella sextelata; an ascomycete fungus of the family Morchellaceae, found primarily in North America. As written in the final summary released by the Montana Department of Public Health and Human Services, “…the toxins in morel mushrooms that may cause illness are not fully understood. However, it is known that using proper morel mushroom preparation techniques, including cooking, can help reduce toxicity and risk of illness. According to documents provided by the restaurant, the morel mushrooms served during March and April 2023 were prepared raw or only lightly cooked, depending on the date of preparation.”
These food tests were performed after a series of interviews performed by the Gallatin City-County Health Department (GCCHD) and the Montana Department of Public Health and Human Services (MT DPHHS) of 63 Dave’s Sushi Customers who ate at the restaurant between the afore-mentioned dates: March 28th and April 27th. The interviews were used as a study to discover the mutual food items consumed by sickened individuals, thus finding the cause for the deadly outbreak. The results clearly pointed towards the consumption of morel mushrooms as being the cause for customer’s development of Gastrointestinal sickness. In accordance with the Centers For Disease Control and Prevention (CDC), the above-listed health departments came to this conclusion through interviewing 22 individuals who dined at Dave’s Sushi Restaurant and did not become ill, as well as 41 customers who became sick after consuming food at Dave’s Sushi.
The final summary of the Dave’s Sushi Restaurant foodborne outbreak was concluded by reminding readers of two impediments the above-described study findings presented: Firstly, the particular aspect of morel mushrooms that caused the outbreak was not found…”Storage of the morel mushrooms, in addition to the differences in cooking method described above, could have played a role in making people sick…” Secondly, even with the use of laboratory processing, the pathogen or toxin contained by the morel mushrooms that was served and caused illness could not be recognized…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. There are scientific gaps in knowledge regarding morel mushrooms in the wider public health, medical toxicology, and mycology realms that need further research in order to better understand how morel mushrooms affect human health…”
As always, mushroom handlers are strongly recommended to proceed with caution; educating oneself on proper mushroom preparation, dangerous fungi, and mushroom-borne illnesses that can oftentimes be fatal, as in this outbreak.