Stressed fungus isn't a fun guy

Dead ants infected with Ophiocordyceps unilateralis, Source: https://en.wikipedia.org/wiki/Ophiocordyceps_unilateralis

Media has been fascinated with the idea of a mind-controlling fungal pathogen for quite some time. Recently, a TV series called "Last of Us" has captivated millions. However, what if fungal pathogens could actually pose a real threat?

In "The Last of Us" video game and TV series, the story is set in a post-apocalyptic world where a fungal infection has ravaged humanity. The infection, known as the Cordyceps brain infection (CBI), is based on a real-life fungus called Cordyceps that primarily affects insects in nature. Cordyceps fungi are actually edible and medicinal fungi used in many cultures with applications in biological control. Cordyceps can grow predominantly on insects but also occur on spiders, nematodes, and other cordyceps (parasite inception anyone?) (Sung et al. 2007, Vega et al. 2009). While the mechanisms responsible for pathogen invasion in the case of Cordyceps are still vague (Baral, B. 2017), and humans have very little to fear from Cordyceps. There is a real danger with other fungal stains that do infect humans and we should be paying attention to them. A list of fungus to keep our eyes on are here: https://www.who.int/publications/i/item/9789240060241

Scientists have been informing governments and the public for years that climate change, plastic use, and forest clearings will increase the chances that we will encounter a novel pathogenic fungus or force a fungus to adapt by invading a new host to survive. Across the global fungus can be lethal and many animal species are at risk of extinction because of different stains, i.e., white-nose syndrome in bats can have a 90% fatality in bat colonies, chytrid fungus in frogs has caused a mass extinction of amphibians globally, stonebrood fungus in honey bees poses a real risk to honey bees, and Candida auris, flagged by the WHO as a critical concern, is invading hospitals around the world, causing blood infections. Mortality can be as high as 60%. The origin of this fungus is still a mystery. These examples highlight how bad the situation is and could get worse. This increase in fungal infections isn't just scary for humans. It has real ecological and evolutionary consequences for many animal systems on Earth.