Foraging and eating wild mushrooms can end up being deadly, as an immigrant woman of Asian descent discovered after eating mushrooms she and her husband had found in a Toronto park.
The risks associated with consuming toxic mushrooms are illustrated in a paper released today in the Canadian Medical Association Journal. Because of the severity of the woman’s poisoning, Canadians are being warned to be wary of eating wild mushrooms because they could be mistaken for edible varieties.
Scientists with the Sunnybrook Health Sciences Centre in Toronto say that foraging for wild mushrooms has become very popular, but identifying edible varieties can still be very difficult. “Distinguishing safe from harmful mushrooms is a challenge even for mycologists,” co-author, Doctor Adina Weinerman, said.
Weinerman and her colleagues say people need to be reminded that poisonous and edible mushrooms can appear almost identical. “This information is especially important for immigrants who might mistake local poisonous mushrooms for familiar edible species from their native land,” they said.
The case study
The case study focuses on a woman who had immigrated from Asia. In August of 2014, she and her husband went foraging for wild mushrooms in a Toronto park. Her husband had previous experience identifying mushrooms in their native land.
She ended up eating the mushrooms that night, and 12 hours later presented at the Emergency Room with severe abdominal pain, nausea, vomiting and watery diarrhoea. Luckily, the patient had also brought along some of the mushrooms she had eaten.
After being admitted to hospital, the woman’s condition continued to deteriorate, and 36 hours after eating the toxic mushrooms, she was transferred to the Intensive Care Unit with liver failure. The on-call liver transplant team was contacted. A liver transplant was expedited in her case, and thankfully, a donor liver was available. She was discharged on immunotherapy 10 days after the transplant.
Corey Stein, a medical resident at Sunnybrook and the University of Toronto, says the woman knew right away what was wrong with her. “When she first came in and was admitted, we weren’t fully aware of the consequences yet,” Stein told Global News.
The mushrooms she consumed are members of the genus Amanita and are responsible for the majority of deaths from mushroom poisoning. These include A. phalloides (accounting for more than 90% of all deaths), A. verna and A. virosa. The species the woman ingested is called A. bisporigera.
A. bisporigera, like most of the species, forms a symbiotic association with tree roots, in this case, Oak trees. This species forms dense, bunches of large, white fruiting bodies during the mid-summer in eastern North America, and they are very striking to see.
There is no antidote for mushroom poisoning, and when someone is poisoned, very aggressive treatment is required. In the U.S., there are 6,000 cases of toxic mushroom poisoning reported every year, most of them being “mild cases.” The latest figures from Canada report around 150 cases of mushroom poisoning annually, with these cases also being mild cases.
The Colorado Mycological Society, in a report updated on February 25, 2015, says: “Even people who ate one of the deadly Amanita species usually survived (though often with significant liver damage). In fact, the two cases of human deaths in Canada or the United States in the past three years where mushrooms were eaten shortly before the death of the individual were not attributed to consumption of mushrooms, but were clearly due to other causes.”
So while death from consuming Amanita mushrooms is possible, prompt medical treatment is needed to avoid liver damage. “If you’re going to pick or forage for mushrooms in the wild, you need to be certain of the species of what you’re ingesting,” Stein said. “We thought it’d be important for the public to be aware of this. It’s dangerous with steep consequences,” he added.
