California is dealing with what experts describe as the largest known outbreak of deadly mushroom poisonings in U.S. history, with 47 confirmed cases since November, four deaths and at least four illnesses that required liver transplants, according to the California Department of Public Health.
The outbreak has stretched across at least 12 counties in Northern California and the Central Coast, far exceeding the typical statewide total of fewer than five cases of mushroom poisonings per year. The initial clusters were identified in the Monterey and San Francisco Bay areas
Most illnesses are linked to amatoxin-containing mushrooms, including death caps (Amanita phalloides) and western destroying angels (Amanita ocreata), both highly toxic species that can closely resemble edible mushrooms.
Monterey County 2026 cases
In January, seven people were hospitalized in Monterey County after consuming wild white cap mushrooms…