Also also: Jamie loses his leg during the crises, mercy fixes him with a new prosthetic, well at least what she can find, which is a peg leg. It’s better than not being able to walk and being clicker food.
His arm is cut off in his boyfriends attempt to save him from turning, only for it to spread farther up his arm afterwards, and for him to die instead. He gets his arm later on when mako and Jamie meet symmetrya (sp)

The Last of Us Infected: Clickers

Clickers are humans in the third stage of the Ophiocordyceps Unilateralis infection. Their appearance is much less human than other infected, as their faces are skewed and scarred. They have had prolonged exposure to the fungus and are completely blind; however, navigation is still possible using an adaptive echolocation (similar to that of bats). This makes an eerie clicking sound, thus earning their nickname.