'The infected' were inspired by an episode of the BBC Documentary Planète Terre (2006) that featured Cordyceps - a killer fungi which invades the bodies of ants and can actually exercise a basic control over the insect's motor functions. The infected ant will climb up high and die in a position that allows the fungus's spores to travel farther and reach another host. It was featured in the episode titled "Jungles" (Jungles (2006)).
The eye charts in the hospital near the end of the game read "RUN YOU R NEARLY THERE DON'T QUIT!!"
One of the reasons for the game's development was that creative director Neil Druckmann believed that storytelling as a whole had become lazy in the game industry and set out to create a rich narrative in The Last of Us.
In the photograph of Joel and his daughter she is wearing an Argentina coloured football shirt. A nod to Gustavo Santaolalla who wrote the score and was born in Buenos Aires, Argentina.
According to the Japanese game manual, Joel and Sarah's last name is Miller. This was confirmed in The Last of Us Part 2.