Since the DayZ zombie mythos is one based on an infection similar to a toxoplasmosis like zombifying parasite rather than re-animation of a dead body, I had this idea about the nature of the infection one gets from eating zombie flesh or being hit by a zombie. It came to me after watching the great dev discussion about 2017 v2.
I don't know exactly what the paranoid effects of sleep deprivation are - haven't lived long enough to experience it, but what if they were also the effects of infection by zombie hit or eating zombie flesh? Perhaps more acute? This would differentiate between the infection from getting too cold or eating human flesh and zombie infection. You'd also become hyper aware that you were around someone who'd eaten zombie flesh if they were not just coughing but also acting funny.
I don't know exactly what the paranoid effects of sleep deprivation are - haven't lived long enough to experience it, but what if they were also the effects of infection by zombie hit or eating zombie flesh? Perhaps more acute? This would differentiate between the infection from getting too cold or eating human flesh and zombie infection. You'd also become hyper aware that you were around someone who'd eaten zombie flesh if they were not just coughing but also acting funny.