Explainer: Can humans fall victim to killer fungi?

Ashley Bu, Reporter

With the release of the series The Last of Us, some have wondered if a zombie apocalypse made up of infected human beings would be possible. However, the chance that humans could be zombified by such a fungus is very unlikely.

Prolonged increases in temperature and climate change can force fungi to adjust to living at higher temperatures in order to survive. This adaptation can allow fungi to thrive at the temperature of the human body (98.6 degrees fahrenheit.) The majority of fungi species are relatively harmless to humans.

The complex structure of our nervous system protects us from mental interference by foreign organisms. The central nervous system is composed of the brain and the spinal cord. Additionally, treatments are also being developed to mellow the symptoms caused from fungal infections.

Most fungi do not pose a huge threat to the human body on their own. Fungi often make their target organisms exhibit drowsy and unenergetic behaviors rather than the aggressiveness of the infected in The Last of Us.

Take “zombie” ants and crickets infected with fungi, for example. The fungus known as ophiocordyceps unilateralis infiltrates the ant’s body in the form of small cells in order to suck out the target insect’s nutrients.

The fungus ophiocordyceps unilateralis complex juts out from a resting insect. Ophiocordyceps causes infected insects to climb up to higher altitudes and latch onto leaves. (Alexey Yakovlev/CC BY-SA 2.0)

Unlike the fungus shown in The Last of Us, ophiocordyceps does not make insects “undead.” Instead, it gives them a variety of other symptoms. The Journal of Experimental Biology states that the fungus controls the jaw of the affected insect and forces it to go into a “death grip” by latching onto an elevated leaf until it dies. The fungus also sucks out nutrients from the affected insect.

Not all fungi are harmless, though. There are still some fungus types that can threaten our livelihood. Candida auris is a species of fungus that has claimed the lives of many victims around the world. According to the Virginia Department of Health, the majority of people infected with this fungus already have another health issue which may have weakened their immune system.

Humans and other mammal species can also exhibit aggression from medically related causes, but they often are due to other causes.

Prion diseases, which are caused by the mass misfolding of proteins within the brain, can drastically alter a person’s behavior. Over time, the individual may become more irritable and lose their basic functions to survive.\

The most commonly known disease that leads to aggression is rabies. It is a disease with no known cure that is a culprit to the deaths of various mammals. The virus can cause bats, raccoons, and canines to become vicious. Humans can also contract rabies if they are bitten by an infected animal. However, once symptoms appear, the fatality rate becomes almost 100%. They will exhibit various forms of aggression until they die. In order to ensure survival, make sure to get treatment and a rabies vaccine as soon as possible after being bit by an animal.

Nonetheless, rabies will not reach the extent of damage that Cordyceps has caused in The Last of Us, as it is not as easily transmissible. New technologies, medication, and knowledge about fungi will continue to help people with fungal infections.