Amanita phalloides Mushroom Poisonings — Northern California, December 2016

Amanita phalloides, colloquially known as the "death cap," belongs to the Phalloideae section of the Amanita family of mushrooms and is responsible for most deaths following ingestion of foraged mushrooms worldwide (1). On November 28, 2016, members of the Bay Area Mycological Society notified personnel at the California Poison Control System (CPCS) of an unusually large A. phalloides bloom in the greater San Francisco Bay Area, coincident with the abundant rainfall and recent warm weather. Five days later, CPCS received notification of the first human A. phalloides poisoning of the season. Over the following 2 weeks, CPCS was notified of an additional 13 cases of hepatotoxicity resulting from A. phalloides ingestion. In the past few years before this outbreak, CPCS received reports of only a few mushroom poisoning cases per year. A summary of 14 reported cases is presented here. Data extracted from patient medical charts revealed a pattern of delayed gastrointestinal manifestations of intoxication leading to dehydration and hepatotoxicity. Three patients received liver transplants and all but one recovered completely. The morbidity and potential lethality associated with A. phalloides ingestion are serious public health concerns and warrant medical provider education and dissemination of information cautioning against consuming foraged wild mushrooms.