Bay Area Death After Eating Wild Mushrooms Spurs New Warnings of Toxic ‘Super Bloom’

Local health officials are warning not to eat foraged fungi after the death last weekend of a Sonoma County resident who had ingested wild mushrooms.

In recent months, California has seen its largest outbreak of mushroom poisonings in at least three decades. There have been 35 cases since November, causing at least three deaths and three liver transplants, according to Sonoma County officials.

They’re urging residents to avoid eating wild mushrooms altogether during what’s been deemed a “super bloom” of toxic death caps — an innocuous-looking varietal that’s often confused for safe-to-eat ones foraged throughout Northern California.

“Eating wild mushrooms gathered without expert identification can be unsafe,” interim health officer Dr. Michael Stacey said. “Some harmful varieties closely resemble edible mushrooms, even to experienced foragers.”

Death caps are often small and come in white, bronze and light yellow and green hues that are similar to harmless field and button mushrooms like Agaricus campestris or Amanita vernicoccora. They don’t have a foul or bitter taste or smell, mycologist Britt Bunyard told KQED in December.

But their looks are deceiving. Death caps have about a 50% mortality rate and are responsible for more than 90% of mushroom-related deaths. The California Department of Public Health in December said that the agency detected two “significant clusters” of poisoning cases in Monterey and San Francisco counties, caused by the amatoxin found in the fungi.

Experts say that people who’ve eaten a toxic mushroom could begin feeling flu-like symptoms, including vomiting, stomach pain, nausea and diarrhea, within six to 24 hours. Even if those symptoms fade, liver damage can still develop over the course of a few days.

While foraging is part of important cultural or culinary traditions for some, the Sonoma County officials are urging residents to avoid eating wild mushrooms at all during the super bloom, which Stacey said was spurred by mild temperatures and early fall rains in Northern California.

The county officials urged residents to keep an eye on children and pets who might come into contact with the mushrooms. They said that cooking, boiling or freezing the poisonous blooms won’t make them safe to eat, and suggested buying mushrooms only from grocery stores and other “trusted” retailers.

If someone does eat a poisonous mushroom, the county said that person should seek medical attention immediately, since treatment becomes more difficult once symptoms start.