Wild mushrooms linked to outbreak of deadly poisoning in Bay Area, Monterey

Amanita phalloides, commonly known as the death cap, is a deadly poisonous basidiomycete fungus in the genus Amanita, on April 13, 2018. Between mid-November and early December 2025, the California Poison Control System identified 21 cases of toxic mushroom poisoning, likely caused by death cap mushrooms. (Bernard Spragg/Public Domain, CC0 via Bay City News)

Poisonous mushrooms are causing an outbreak of serious illness that’s killed one adult and caused severe liver damage in 21 children and adults in the Bay Area and Monterey since mid-November, health officials say.

The fungi known as “death cap mushrooms” present such a high risk that the Department of Public Health on Friday issued an “urgent advisory” encouraging the public to temporarily avoid foraging for and eating any wild mushrooms.

“Death cap mushrooms contain potentially deadly toxins that can lead to liver failure,” said Dr. Erica Pan, state public health officer. “Because the death cap can easily be mistaken for edible safe mushrooms, we advise the public not to forage for wild mushrooms at all during this high-risk season.”

“Significant clusters” of the dangerous mushrooms have been reported in the Monterey and San Francisco Bay Areas, although there is risk statewide, the health agency said.

The death cap (Amanita phalloides) can easily be mistaken for safe, edible mushrooms due to their similar appearance and taste, health officials said.

“Cooking, boiling, drying, or freezing these mushrooms does NOT make them safe to eat,” the health agency said.

First symptoms of poisoning — including watery diarrhea, nausea, vomiting, abdominal pain, and dehydration — can occur within 6 to 24 hours after eating the mushroom and usually go away within a day.

“However, this brief improvement can be deceptive, as patients may still develop serious to fatal liver damage within 48 to 96 hours after eating the mushrooms,” the health department said.

As of Friday, the California Poison Control System at (800) 222-1222 identified 21 cases of suspected mushroom poisoning since mid-November.

Several patients have required intensive care, with at least one person potentially needing a liver transplant and one adult fatality, the state said.

Death cap mushrooms are found in many parts of California, particularly near oaks and other hardwood trees, including pine trees. Rain in the fall and winter months create ideal conditions for their growth, the state said.

More information is available at the California Poison Control System or visit the health department website.

The post Wild mushrooms linked to outbreak of deadly poisoning in Bay Area, Monterey appeared first on Local News Matters.

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