Viruses and infections have long been the tool of science-fiction and dystopian stories but the COVID-19 pandemic has made the threat of outbreaks sweeping the world all too real. Fungal infections are not so fictional - take yeast infections for example. Belonging to the Candida genus, yeast infections are incredibly common and are treated with antibiotics. To those with compromised immune systems, fungal infections can pose more of a threat with research indicating an estimated 1.7 million deaths per year.
The Ophiocordyceps unilateralis featured in The Last of Us is a mutated strain of the fungus found in ants. Spreading through spores, the cordyceps attaches to the exoskeleton and begins to alter the behaviour of the host with the goal of survival and dispersal. Mind altering fungus are more common than you might think - what do magic mushrooms do again?
As the opening scene of the show highlights, cordyceps cannot survive humans' body temperature, but uses global warming to imply it may adapt to survive higher temperatures in the future. In reality, the World Health Organisation released a report last year that identified the 19 "most wanted" fungal pathogens that are most dangerous to humans. There are an estimated 12 million species of fungi worldwide and the majority have never been categorised. In terms of the Ophiocordyceps species in particular, over 200 species have been identified that can infect hosts from 10 insect orders along with spiders.
Included in WHO's list is Coccidioides which are soil dwelling fungi that can be found in Mexico, South America and south west US. The fungi can cause Valley Fever which is similar to the flu and infects roughly 150,000 people in the US each year, with around 75 dying from it. It has been observed that the range within which the fungi is found has increased, being found as north as the state of Washington. According to to reports by the CDC, cases of Valley Fever have gone up 400% between 1998 and 2015 suggesting climate change is to blame.
Mucormycosis, also known as "black fungus syndrome", is a dangerous but rare fungal infection that doctors believe has appeared to have capitalised on the weakened immune systems as a result of COVID. The symptoms match the ominous name - blackened skin, blurred vision, facial swelling, and potentially comas. Fungal infections do not transmit between people but is usually picked up from the environment. Take murcormycosis as an example. Chances are you will never pick it up in the UK but if you were in India, it is 70-80 times more prevalent.
So, are fungal infections a bigger threat to our health and the future of humanity than we realise? Chances are if you have a healthy immune system, you will be fine in the face of a fungal infection. Efforts will likely focus on protecting immunocompromised individuals. With so many fungal species and antibiotic resistance on the rise, scientists have a difficult task on there hands. Fungal infections may be a potential threat in the future, but fear not, a Last of Us style outbreak seems unlikely.