Calls to provincial health officials in B.C. about exposures to wild mushrooms found in backyards, boulevards and natural areas have hit an all-time high over the past six years.
New data released by the B.C. Centre for Disease Control (BCCDC) shows that officials with the B.C. Drug and Poison Information Centre fielded 325 calls about possible poisoning from mushrooms in 2020, an increase from 254 calls in 2019.
In 2019, the BCCDC warned about a rise in mushroom poisonings as the deadliest mushroom in the world, the death cap mushroom, continued to proliferate in the province in mostly urban areas as an invasive species.
"It is important to be aware of dangers from consuming unidentified mushrooms, especially death cap mushrooms," the BCCDC said in a release at the time.
The BCCDC also said that around two-thirds of all mushroom poisonings involve children under the age of five.
Lurking underground for years
Death cap mushrooms, which are a somewhat plain-looking white mushroom, were first discovered in B.C. in 1997 in Mission. Experts believe they arrived here on the infected roots of non-native trees imported from Europe decades earlier.
The fungus lurked underground for years before conditions were right for fruiting, which is most often found under trees in urban areas.
Toxins in the death cap, also known as Amanita phalloides, kill more people than any other mushroom worldwide. They attack the liver, kidney and other organs. Ingesting one mushroom cap is enough to kill. Early intervention and medical treatment is essential for survival.
Paul Kroeger with the Vancouver Mycological Society has been tracking death cap mushrooms in the province since they began appearing.
"It is a concern especially because the death cap mushroom and certain other mushrooms of concern are coming up around peoples' homes," he said. "They're there in close proximity to young children and pets."
Five years ago, a three-year-old boy in Victoria died after ingesting a death cap mushroom while foraging with his family in the city. It was the first recorded death in B.C. from a death cap mushroom.
"It was very, very upsetting for everybody," said Kroeger, who also helps provincial officials identify mushrooms.
Kroeger says the fruiting of mushrooms is tied to weather conditions and the fungi like wet, nutrient-poor soil.
The BCCDC says 2020's wet spring may have contributed to more mushrooms and more calls about potential poisonings.
It also said in an email that people's behaviour during the pandemic, such as being outside more, could have contributed to the increase in calls.
Calls up, death cap sickness low
Kroeger said that while death cap mushrooms are proliferating, so is awareness about them.
He said that while the number of calls about poisonous mushroom exposures overall has increased, the number of confirmed sicknesses caused by ingesting death cap mushrooms doesn't appear to be increasing. There have been no human deaths from death cap mushrooms since 2016.
"So to me it indicates our efforts at increasing public awareness about the hazard has been successful," he said.
The BCCDC also said that on average there has been one confirmed non-fatal human poisoning from death cap mushrooms per year over the past six years.
The agency says that for 2021, up until Oct. 24, there were 183 calls about potential mushroom poisonings. Kroeger says the hot dry summer was not conducive to the mushrooms fruiting.
If you suspect you have eaten a death cap mushroom, the BCCDC says you should immediately go to an emergency room, take specimens of the mushroom with you to the hospital and provide information about the specific location where the mushrooms were found.
People can also call the Drug and Poison Information Centre at 1-800-567-8911.
The symptoms of death cap mushroom poisoning include low blood pressure, nausea and vomiting, which begins eight to 12 hours after ingestion. After up to 24 hours have passed, the symptoms can disappear. Symptoms of liver and kidney damage start three to six days after the mushrooms were consumed.
The BCCDC wants people who find death cap mushrooms to report them to the province.
An online atlas created through the University of B.C. shows where death cap mushrooms have been discovered in B.C.