Can a fungal infection really create zombies like in 'The Last of Us'?

In The Last of Us video game, which is the basis of the eponymous TV drama series, there are many types of zombie-like creatures caused by humans getting infected with a mutant fungus. — Naughty Dog

I have been watching the drama series The Last of Us on HBO, and they talk about this Cordyceps fungus that can infect humans and control their minds. Does this Cordyceps fungus actually exist?

In The Last of Us, which is based on the eponymous video game, a Cordyceps fungus variant allegedly attacks humans and hijacks the mind, controlling a person until they are completely devoured from within.

This concept was actually inspired by a real-life David Attenborough documentary of a fungus taking over ants and controlling them.

The real-life fungus in question is Ophiocordyceps unilateralis, also known as zombie ant fungus.

Don’t worry though, it is only known to infect ants.

Once infected, the ants behave very differently and become like “zombie ants”.

They behave completely for the benefit of the fungus’ growth and transmission.

The ants will attach themselves to leaves and lock their jaws, leading to their death ultimately.

The fungus then sprouts tendrils and releases more spores to begin its lifecycle all over again.

So yes, something like the Cordyceps fungus really does exist.

But can fungi affect humans?

They are already infecting humans.

A fungal infection is also known as mycosis.

The commonest fungal infections in the world affect our skin, nails and lungs.

Fungi reproduce by releasing spores that can be inhaled or transmitted via direct contact.

Some common fungal infections that affect our skin and nails are athlete’s foot, jock itch, ringworm, yeast infection and fungal infection of the nail, also known as onychomycosis.

Most fungi aren’t harmful.

Of the more than 150,000 known species, only about 200 can infect humans.

Nevertheless, more than 150 million severe fungal infections occur globally every year, and result in about 1.7 million deaths.

Most fungi prefer cooler temperatures – around 10°C.

Before you panic, this means they prefer it if your body temperature is around 10°C, but our body temperature is typically around 37°C, regardless of the outside temperature.

This is why most fungal infections in humans tend to concentrate on our skin, where it is cooler.

Ringworm is a common fungal infection that doesn't involve worms at all. — SZETOO WEIWEN

Fungal skin infections are not dangerous, right?

You are right, most fungal infections are not dangerous.

For example, a common fungal infection is athlete’s foot, also known as tinea pedis.

It is caused by dermatophytes – a group of fungi that thrive in warm and humid areas, especially between your toes.

That is why it is called athlete’s foot, because you can get it from damp locker rooms and shower floors.

It affects the skin on your feet, and also your hands and nails.

Meanwhile, jock itch is known as tinea cruris, and affects your groin area, inner thighs and buttocks.

It is also caused by dermatophytes.

It mostly affects men and boys, which is why it is known as “jock” itch; but it can also affect women.

This one causes redness, swelling and itching in the affected skin area.

There may be a rash, leading to flaking or cracking skin.

It gets worse when you exercise.

Dermatophytes also cause ringworm, which forms red rings on your skin and scalp.

The word “worm” is misleading as no actual worms are involved in the infection.

Yeast, such as Candida albicans, like to infect your skin, mouth, gastrointestinal tract, urinary tract and genitals.

When it affects your mouth, it is called oral thrush, which are white patches in your mouth and throat.

In women, vaginal yeast infections can cause pain, itchiness, discharge and redness around your groin area.

Because all these fungal infections can be easily treated via antifungal creams and ointments, or even antifungal tablets, they are not life-threatening.

What are dangerous fungal infections?

The fungal infections that are dangerous don’t normally cause infections in healthy human beings.

But they are dangerous to people with weakened immune systems, e.g. if you have AIDS (Acquired Immunodeficiency Syndrome) or cancer, or are on immunosuppressive drugs (for organ transplants).

These are called opportunistic infections, because they take the “opportunity” to infect you when your body’s defences are down.

But once they infect you, they can be very devastating.

The World Health Organization (WHO) recently listed a group of fungal pathogens in the “dangerous to humans” list.

These include four fungi pathogens: Cryptococcus neoformans, Aspergillus fumigatus, C. albicans and Candida auris.

What does Cryptococcus neoformans cause?

In people who have weakened immune systems, C. neoformans can infect their lungs, brain and spinal cord, as well as other parts of the body.

This type of infection is called cryptococcosis.

In your lungs, it can cause a pneumonia type of infection that gives you a cough, shortness of breath, chest pain and fever.

In your brain, it can give you cryptococcal meningitis and cause headaches, fever and neck pain – which are the hallmarks of meningitis.

It usually spreads from your lungs to the brain.

See Tell Me About next fortnight for how climate change can affect dangerous fungal infections.

Dr YLM graduated as a medical doctor, and has been writing for many years on various subjects such as medicine, health, computers and entertainment. For further information, email [e-mail]. The information provided is for educational and communication purposes only, and it should not be construed as personal medical advice. Neither The Star nor the author gives any warranty on accuracy, completeness, functionality, usefulness or other assurances as to such information. The Star and the author disclaim all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.