California has experienced an 'unprecedented' outbreak of toxic mushroom poisonings, with four deaths and 40 hospitalisations between late November 2025 and early February 2026, according to the state health department. This far exceeds the typical annual average of fewer than five cases.
The poisonings have been linked to the death cap mushroom (Amanita phalloides), which can resemble edible species. Victims include a seasonal farm worker couple from Oaxaca, Mexico, and range in age from 19 months to 67 years. Several people have required liver transplants.
Rudy Diaz, resident mycologist of the Los Angeles Mycological Society, noted that the outbreak has made the public cautious. However, he said experienced foragers are not panicking, as finding mushrooms in southern California requires skill and knowledge. Jess Starwood, a forager and educator, warned that novice foragers can easily mistake death caps for edible puffballs or other species.
The epicentre of the first 35 incidents was Salinas, a central coast town with a large population from central Mexico, where mushroom foraging is common. Diaz suspects the death cap was mistaken for edible Amanita species familiar in Mexico. The state health department has issued a flyer with QR codes in nine languages, including Spanish, Mandarin, Mixteco, Russian and Ukrainian.
Climate change may be contributing to the spread of lesser-known mushrooms, with wet winters producing more fungi and non-typical species appearing in new areas. The western destroying angel mushroom (Amanita ocreata) is also highly toxic and common in coastal regions through April. Experts advise inexperienced foragers to join local mycological societies or foraging groups to learn safe identification.
