Outside the QZ's, the Infected roamed freely and would continuously taint the environment with deadly spores as the fungus kept growing within their bodies.įor humans that have been exposed to a mutated strain of Ophiocordyceps Unilateralis, the fungus attacks the brain and begins to alter the behaviour of its host. In the US, Quarantine Zones were established where uninfected could reside, though living conditions would be consistently poor due to the shortages of supplies and the perpetual state of martial law. With society on the verge of collapse, the remnants of the world's governments took drastic steps to protect their remaining populations. Attempts to prevent the infection from spreading beyond US borders failed and it soon reached pandemic proportions, threatening to wipe out mankind. According to the storyline of The Last Of Us, the CBI plague spread rapidly across the United States of America in September 2013.
