San Mateo County latest to warn residents about wild mushroom poisonings
By Tim Fang
Officials in San Mateo County are the latest in the Bay Area to warn residents to not forage for wild mushrooms, amid a rise in mushroom poisonings that have led to illnesses and even deaths.
On Thursday, health officials issued a warning after the illness of a county resident linked to death cap mushroom poisoning. The department did not provide the person’s name, age, or where in the county they lived.
“Death cap mushrooms are extremely dangerous and can be mistaken for mushrooms that look safe to eat. No amount of cooking, boiling or drying makes these mushrooms safe,” health officer Dr. Kismet Baldwin-Santana said in a statement.
The health officer said the safest choice at the moment is to avoid eating any wild mushrooms.
“Even experienced foragers should exercise extreme caution and should not rely on AI-assisted field identification to distinguish between safe and poisonous mushrooms,” Baldwin-Santana added.
The warning comes as state and local health officials see an “unprecedented” rise in serious illnesses and deaths associated with poisonous mushrooms.
While fewer than five mushroom poisoning cases are reported in a typical year, there have been at least 35 poisoning cases between Nov. 18, 2025 and Jan. 6, according to the California Department of Public Health. Officials said at least three people have died in the poisonings, while another three required liver transplants.
Meanwhile, health officials in Sonoma County announced a resident died from mushroom poisoning last weekend.
The cases have been concentrated in the Monterey Bay and San Francisco Bay Area, but officials noted death cap mushrooms can be found across California, particularly near oaks, other hardwoods and some pines.
Officials said symptoms of death cap poisoning can begin six to 24 hours after eating, which include watery diarrhea, nausea, vomiting, abdominal pain and dehydration. Symptoms may improve briefly before severe liver failure develops about one to four days later.
Anyone who may have consumed wild mushrooms or has symptoms should seek medical attention immediately. Additional information can be found by contacting poison control at 1-800-222-1222.
