“The Last of Us”: Is it possible that a fungus pandemic creates zombies in real life?

HBO’s new series “The Last of US” presents a post-apocalyptic scenario in which thousands of people are turned into zombies after a fungus infection becomes a pandemic. The series was the second biggest premiere this year on the HBO MAX platform and the third episode is available this Sunday (29).

The scenario may be fanciful, but the type of fungus represented in the series actually exists. They are fungi of the genera Cordyceps and Ophiocordyceps and in real life they actually turn their victims into zombies.

The spores of this type of fungus enter the victim’s body, where the fungus grows and begins to hijack its host’s mind until it loses control and is compelled to climb to higher ground. The parasitic fungus devours its victim from within, extracting every last nutrient as it prepares for its grand final act.

Then – in a scene more disturbing than the scariest horror movie – a tentacle of death erupts from the head. This body of the fungus spreads spores all around it – dooming other victims to the same fate if they are too close to be infected.

Lucky for us, fungi of this genus are capable of contaminating only ants – and only a few species. Other similar fungi contaminate other insect species in a similar way. This BBC documentary shows an ant infected with the fungus:

The workings of these parasitic fungi inspired the video game The Last of US, on which the HBO series was based.

In the plot of these works of fiction, Cordyceps fungi become capable of infecting humans and cause a pandemic capable of leading to the collapse of society.

But in the real world, is a Cordyceps pandemic – or caused by another fungus – something that could really happen?

“I think we underestimate fungal infections at our peril,” says Dr Neil Stone, leading fungal expert at London’s Hospital for Tropical Diseases. “We’ve been doing this for too long and are completely unprepared to deal with a fungal pandemic.”

List of dangerous fungi for humans

At the end of October last year, the World Health Organization (WHO) released its first list of fungi with the highest risk to public health.

The fungi on the list are indeed menacing, but – to our relief – none on the list are capable of turning humans into zombies.

Why not?

Microbiologist Charissa de Bekker at the University of Utrecht in the UK studies how Cordyceps fungi zombify ants and says she doesn’t see how this could happen to people.

“Our body temperature is simply too high for most fungi, including Cordyceps,” he explains. “Their nervous system is simpler than ours, so it’s much easier to hijack an insect brain than the complex human brain.”

In addition, she explains, their immune systems are very different from ours, which would also make this “kidnapping” difficult.

Most parasitic Cordyceps species have evolved over thousands of years to specialize in infecting just one species of insect. Most don’t jump from one insect to the next.

“For this fungus to be able to go from an insect to us and be able to infect us in the same way, it’s a very long distance,” says Bekker.

mortal threats

However, the threat of a fungal pandemic is very real, although it has been underestimated for a long time. “People think of fungi as something trivial, superficial or unimportant,” says Dr. Neil Stone.

Only a few of the millions of species of fungi cause disease in humans. However, some of these can be much worse than an infected toenail or chilblain.

Fungi kill about 1.7 million people a year – about three times as many as malaria.

The WHO has identified 19 different fungi that it considers to be of concern.

The most serious ones are Candida auris, Cryptococcus neoformans and Mucormycetes – which eats our flesh so quickly that it leads to serious facial injuries.

The global threat of candida auris

THE candida auris it’s a yeast – and it gives off the same fermentation smell as a brewery or bread dough.

But unlike the beneficial yeasts we use for food, candida auris it’s a terrible parasite.

It contaminates the blood, nervous system and internal organs. The WHO estimates that half of people infected by candida auris die.

The first documented case was in the ear of a patient at the Tokyo Metropolitan Geriatric Hospital in 2009, and since then the fungus has spread around the world.

THE candida auris it’s very difficult to fight – some strains are resistant to all the antifungal drugs we have. For this reason, it is often called the “superfungus”.

Transmission is mainly through contaminated surfaces in hospitals – it’s a really difficult fungus to clean completely. Often, the solution is to close entire hospital wards, something that has already happened in the United Kingdom.

Neil Stone says that the candida auris it is the most worrying type of fungus and we cannot ignore it, as a pandemic caused by it could lead to the collapse of health systems.

deadly fungus

Another deadly fungus – the Cryptococcus neoformans – is capable of getting into people’s nervous systems and causing devastating meningitis.

The British Sid and Ellie had contact with the disease in the first days of their honeymoon in Costa Rica. Elle began to feel sick and her initial symptoms – headaches and nausea – were attributed to too much sun. But then she started to have very strong spasms and seizures.

“I’ve never seen anything worse, I felt so helpless,” Sid tells the BBC.

Tests done showed inflammation in his brain and identified Cryptococcus as the cause. Fortunately, Ellie responded to the treatment and came out of the coma after 12 days on a ventilator.

“I just remember screaming,” says she, who had delusions when she was infected.

Now she is recovering well.

Ellie says she “never” thought a fungus could do this to a person. “You don’t think you’re going to almost die on your honeymoon.”

black fungus

Another threat to public health is Mucormycetes, also known as black fungus. It causes a very serious disease called mucormycosis, which usually affects people with compromised immune systems.

It reproduces so quickly that, if it’s being grown in a lab, it can make the lid of a petri dish pop off.

“When you let a piece of fruit go bad and the next day it turns into mush, it’s because there was a mucormycetes fungus inside it,” says Dr Rebecca Gorton, a scientist at HSL, the health services laboratory in London.

She says the infection is rare in humans, but it can be really serious when it happens.

The fungus attacks the face, eyes and brain and can be fatal or leave people severely disfigured. An infection spreads just as quickly in the body as it does in fruit or the lab, Gorton says.

During the Covid-19 pandemic, there has been an explosion of black fungus cases in India. More than 4,000 people died. It is believed that the weakened immune system of the people and the high levels of diabetes in the country helped in the proliferation of the fungus. About 30 cases of mucormycosis contamination were recorded in Brazil in 2021.

Should we take fungus more seriously?

Fungi generate infections very different from those caused by bacteria or viruses. When a fungus makes us sick, it is almost always picked up from the environment rather than spread through coughing and sneezing.

We’re all exposed to fungus all the time, but they usually need a weakened immune system to thrive.

Stone says a fungal pandemic would likely be very different from the Covid pandemic — both in how it spreads and in the type of people it infects.

He thinks the threat exists because of “the volume of fungi that exist in the environment” and because of “climate changes, international travel, the increasing number of cases and the profound disregard we have in terms of treatments”.