The Scourge is a fictional disease featured in the video game series The Last of Us. It is caused by a mutated strain of the Cordyceps fungus, which infects humans and takes control of their bodies. Infected individuals exhibit aggressive behavior and lose their cognitive functions, becoming dangerous to others. The disease spreads through bites and spores, leading to a post-apocalyptic world where survivors must navigate the threats posed by both the infected and other humans. The Scourge serves as a central element in the narrative, highlighting themes of survival, loss, and the impact of infection on society.