A California man died last weekend afterconsuming "death cap" mushrooms— the third such death in the state since November.
California has been contending with an unusual spate of poisonings from foraged mushrooms: 35 cases were recorded from Nov. 18 to Jan. 4. In an average year, fewer than five would be expected.
"The numbers we're dealing with this year are comparatively off the charts," said Sheri Cardo, a communications specialist for the state health department.
The problemprompted a warningfrom the health department on Dec. 5, in which officials strongly discouraged residents from consuming any foraged mushrooms. The advisory described clusters of poisoning cases around Monterey and the San Francisco Bay Area. The affected patients had mistaken toxic varieties for mushrooms that are safe to eat, the health department said.
The most recent death was in Sonoma County — the first from wild mushrooms there this season, according to the county health department.
Dr. Michael Stacey, the interim health officer for Sonoma County, instructed residents to only purchase mushrooms from trusted grocery stores and retailers, adding that some "death cap" mushrooms closely resemble edible varieties.
"Early rains and a mild fall have led to profusion of the toxic death cap mushrooms in Northern California," Stacey saidin a press releaseon Thursday.
Last month, the California Poison Control System said that some of the people who had been poisoned by death caps spoke Spanish and might have relied on foraging practices developed outside the United States. Heather Hallen-Adams, the toxicology chair of the North American Mycological Association, previously told NBC News that death cap mushrooms look similar to other species in its genus, Amanita, that are often collected in Mexico and are safe to eat.
The toxin in death cap mushrooms, called amatoxin, can damage the kidneys, liver and gastrointestinal tract if ingested. Symptoms of amatoxin poisoning can take up to 24 hours to appear and include mild nausea, vomiting, diarrhea and stomach pain. More severe reactions, like fatal liver damage, can develop within two to three days.
Hallen-Adams said about 90% of fatal poisonings from mushrooms are due to amatoxin poisoning.
Small amounts of the death cap mushroom — a volume as small as a standard sugar cube — can be a fatal dose.
Three patients in California with wild mushroom poisoning have required liver transplants, according to the health department.
The death cap mushroom, also called Amanita phalloides, is an invasive species that originated in Europe and came to California in the 1930s, most likely with imported nursery trees. In California, it typically grows near oak trees and occasionally pines. The mushroom is usually a few inches tall but can grow larger and has white gills, a pale yellow or green cap and a ring around its stalk.
U.S. Poison Centers typically receive around 52 calls a year about amatoxin poisoning, according to Hallen-Adams, though not all cases are reported to the centers.
This season's risk might be winding down in California, according to Mike McCurdy, president of the Mycological Society of San Francisco. A frequent mushroom collector, McCurdy said he had seen far fewer death cap mushrooms during recent outings, whereas he saw hundreds of them during a two- to three-hour walk in Sonoma County earlier this winter.
On a recent walk near Lafayette, California, he found only one, he said: "I think we're getting close to the end."
