- James Gallagher
- BBC, health and science reporter
image source, HBO/Warner Media/Liane Hentscher
A scene from HBO’s post-apocalyptic television drama The Last of Us showing a body being consumed by Cordyceps mushrooms
Let me introduce you to something truly horrible: the fungus that turns its victims into zombies.
Its spores enter the body. Later the fungus grows and begins to hijack the mind of its host, until he loses control and is forced to climb to higher ground.
The parasitic fungus devours its victim from the inside, extracting every last nutrient, as it prepares for its grand finale.
Next, in a scene scarier than the scariest horror movie, a tendril of death sprouts from the head. The overflowing body of the fungus spills spores all over it, condemning others to the same zombie fate.
It sounds like a work of fiction. But the kingdom of fungi, different from that of plants and animals, ranges from edible mushrooms to parasites that feed nightmares.
fungi species Cordyceps y Ophiocordyceps they are very real. In a sequence of the series Planet Earth of the BBC can be seen how one of them takes control of an ant.
That zombie ants clip inspired “The Last of Us,” possibly the best video game I’ve ever played, and now a hit TV series that follows the same plot.
Both in the game and on TV, the Cordyceps it makes the leap from hunting insects, its usual victims, to infecting humans. And unleashes a pandemic that leads to the collapse of society.
But in the real world, is it possible for a pandemic to occur? Cordyceps or one caused by another fungus?
“I think we underestimated fungal infections at our peril”says Dr Neil Stone, a leading fungal expert at London’s Hospital for Tropical Diseases.
“We’ve already been at it for too long and we’re not prepared to deal with a fungal pandemic.”
At the end of October last year, the World Health Organization (WHO) published its first list of life-threatening fungi.
There are some nasty bugs in there, but you’ll be relieved to know that those Cordyceps zombifiers do not appear.
image source, Getty Images
A caterpillar eaten by a parasitic fungus, with the tissues releasing spores.
Dr. Charissa de Bekker, a microbiologist at Utrecht University in the Netherlands, has studied how Cordyceps they create zombified ants and says he doesn’t see how that could happen to people.
“Our body temperature is simply too high for most fungi to settle and grow well.and this is the same for this Cordyceps“.
“Their nervous system is simpler than ours, so it would definitely be easier to hijack an insect’s brain than our brain. Also, their immune systems are very different from ours,” he says.
Most parasite species Cordyceps they have evolved over millions of years to specialize in infecting a single species of insect. Most do not jump from one insect to another.
“That this fungus can be transmitted from an insect to us and cause an infection it’s a big jump“, affirms Bekker.
Threats posed by fungi have long been dismissed. “People think it’s something trivial, superficial, or unimportant,” says Dr. Stone.
Only a handful of the millions of fungal species out there cause disease, but some can be much worse than an irritating bout of athlete’s foot or an infected toenail.
Fungi kill about 1.7 million people a year, about three times more than malaria.
Deadly Threats Greater Than the Cordyceps
The WHO has identified 19 different fungi that it considers to be a major concern.. They include the sudden appearance of a deadly superbug, the White earsand a fungus, the Mucormyceteswhich eats our meat so quickly that it causes serious facial injuries.
Dr Neil Stone invites me to the Health Services Laboratory (HSL) in London, where samples from UK patients are tested to see if infections are caused by a fungus and what treatments might work. We discuss some of the biggest fungal dangers.
Neil Stone says that we ignore the fungus Candida auris “at our peril.”
The White ears It’s the first we’ve seen.
It is a yeast-like fungus and up close you can feel that strong smell of a brewery or bread dough.
If it enters the body, can invade blood, nervous system, and internal organs. The WHO estimates that up to half of people die if they have an invasive infection of White ears.
“It’s like a monster that has appeared in the last 15 years, but now it’s all over the world,” Stone says.
The first documented case was in the ear of a patient at the Tokyo Metropolitan Geriatric Hospital in 2009.
image source, The Last of Us
Infections in “The Last of Us” are terrifying.
Naturally, the White ears it ignores antifungal drugs and some strains are resistant to all the drugs we have. Therefore, it is considered a superbug.
Transmission is mainly through contaminated surfaces in hospitals. Attaches to IV lines and blood pressure cuffs. It’s really hard to clean. The solution is usually to close entire pavilions.
Stone points out that it is the “most worrying” fungus and that “we ignore it at our peril” since if it proliferates “it could shut down entire health systems.”
Another killer mushroom, the Cryptococcus neoformanscan penetrate the nervous system of people and cause devastating meningitis.
The case of Sid and Ellie
Sid and Ellie were just in the first days of their honeymoon in Costa Rica when she began to feel ill.
image source, Sid and Ellie
Sid and Ellie had their wedding before Ellie contracted a yeast infection.
His initial symptoms (headaches and nausea) were attributed to too much sun, but then he began to shiver and have convulsions. They had to wrap her in a hammock and take her on a boat for medical help.
“I’ve never seen anything so horrible and above all I’ve never felt so helpless,” says Sid.
Exams showed swelling in his brain and tests identified the Cryptococcus. Fortunately, Ellie responded to the treatment. She came out of a coma after 12 days connected to mechanical ventilation.
“I just remember screaming,” he says. She had delusions, including having triplets and that her husband had gambled away her money. “So the first thing I told him was it’s over,” she says.
Now, Ellie is on the mend. She never thought that a mushroom could do such a thing to a person. “You don’t think you’re going to go on a honeymoon and almost die.”
Mucormycetes, also known as black fungi, cause the flesh-eating disease mucormycosis.. Some know him by a nickname that reveals his insidious nature: the cover lifter.
Mucormycete fungi can grow rapidly.
Starts fast. This image shows that after just 24 hours of growth in a petri dish, you can lift the lid.
“When you have a piece of fruit and the next day it turns to mush, it’s because it has a mucor fungus. [Mucormycetes] inside,” says HSL clinical scientist Dr. Rebecca Gorton. She says it’s rare in humans, but it can be a “really serious infection.”
The black fungus is an opportunist that takes over people with weak immune systems. It attacks the face, eyes, and brain and can be fatal or leave people severely disfigured. A serious infection “grows as fast” in the body as it does in the fruit or in the laboratory, warns the specialist.
During the Covid pandemic, there was an explosion of black fungus cases in India. More than 4,000 people died. It is believed that steroids taken for covid, which weakened the immune system of patients, and high levels of diabetes, helped the fungus proliferate.
should we take a mushrooms more seriously?
Fungi generate very different infections than bacteria or viruses. When a fungus makes us sick, we almost always take it in from the environment rather than spread it through coughs and sneezes.
We are all regularly exposed to fungi, but they often need a weakened immune system to get off the ground. As medicine keeps us alive, like survivors of some cancer treatments, more people have weaker immune systems.
Dr. Stone says that A fungal pandemic would likely take “a different form” than Covidboth in the way it spreads and the type of people it infects.
He thinks the threat is there because of the “sheer volume of fungus in the environment…climate change, international travel, the increasing number of cases, and its profound neglect in terms of the treatments we have.”
Mushrooms may not turn us all into zombies, but they can cause a lot more problems than we think.
