Vancouver Coastal Health warned yesterday (July 4) on Twitter that a so-called death cap mushroom "has been seen in Vancouver".
The toxic death cap (scientific name Amanita phalloides) is known as the world's deadliest mushroom because experts think that as much as 90 percent of the world's mushroom fatalities can be attributed to it.
Even small doses of amatoxin, the mushroom's toxic compound, can be fatal. The poison—for which there is no antidote—attacks the kidneys and liver, with the most serious symptoms showing up several days after ingestion. Cooking, freezing, or drying the fungus will not negate or diminish the toxic effects.
Last March, UBC researchers published a paper in the B.C. Medical Journal warning that A. phalloides was expanding its range in southern coastal B.C. The paper emphasized the need for education so mushroom foragers, health-care providers, and all citizens could familiarize themselves with both identification of the species during its growing phases and the symptoms of amatoxin poisoning.
Prompt hospital care is critical for amatoxin treatment, and organ transplantation is the only "cure" if acute liver failure takes place. Even with improved contemporary treatment, about half of all poisoned children under 10 die, with an overall fatality rate of about 22 percent. (In 2016, a Victoria child died after ingesting a death cap.)
The health authority did not disclose a location where the mushroom was seen in Vancouver, but its growing season here—where it was first detected more than 20 years ago—is between June and November, and sightings of it, and most mushrooms, increase after periods of sustained rain.
The UBC researchers pointed to the death cap's close resemblance to species of edible mushrooms such as straw mushrooms and puff balls as a compelling reason to be certain of identification before consuming foraged fungus.
The B.C. Centre for Disease Control (BCCDC) published a bulletin in 2018 that noted more than 100 vancouver locations identified by the Vancouver Mycological Society as places where death caps had been found.
The health centre advised that the death cap probably originally came to the Lower Mainland and southern Vancouver Island on the roots of imported trees that were planted on boulevards in Victoria and Vancouver.
For more BCCDC death cap information and links, go here.