Caution advised when foraging for morel mushrooms

In the spring of 2023, a foodborne outbreak occurred in Montana after a Bozeman restaurant served raw and undercooked morels. A total of 51 people with gastrointestinal (GI) symptoms were reported as part of this outbreak, including three hospitalizations and two deaths. Individuals became ill quickly after consumption, typically within one hour after the restaurant meal. An investigation into this outbreak found that consumption of morels at the restaurant was strongly associated with GI illness. Consumption of raw morels was more strongly associated with illness than was consumption of partially cooked morels, although even partially cooked morels were associated with illness.

The mushrooms served as part of this outbreak were confirmed through testing to be Morchella sextelata, a species of true morel. Despite additional laboratory testing, the presence of a specific toxin was not confirmed in the morel sample. The toxins in morel mushrooms are not well characterized, and further research needs to be done to better understand morel toxicity.

Outbreaks and illness linked to consumption of morels seem to occur infrequently, but may occur more often than public health professionals or medical providers currently realize because symptoms may not be severe enough to cause individuals to seek care or the illness may not be known to be associated with morel consumption. The 2023 Montana outbreak is not the first GI outbreak linked to the consumption of morels, either prepared raw or cooked to varying degrees.