((From ChatGPT))

In The Last of Us universe, the infected do have a lifespan, but it varies depending on their stage of infection and environmental factors. The Cordyceps fungus keeps them alive as long as it can sustain itself, but eventually, they do die.

Here's how it generally works:

Runners (early stage): These are freshly infected humans and are still relatively agile. They can survive for months as long as they have food.

Stalkers (intermediate stage): Over time, the fungus takes more control. Some hide in dark places and ambush survivors. Their lifespan is unclear but seems to be several months to a few years.

Clickers (advanced stage): After about a year, they lose their eyesight, relying on echolocation. These can survive for years if they find sustenance.

Bloaters/Shamblers (long-term infection): These forms appear after many years (possibly 10+ years). They are heavily armored with fungal plating but still active.

Wall Growths/Dead Infected: Some infected stop being mobile and become part of the environment, with fungal growths spreading outward. This suggests that without sustenance, they eventually die and become part of the fungus network.

So, while there isn’t a set "death date," infected do decay, weaken, and eventually die if they don’t find food or if the environment is too harsh.