Zombies in the Living Dead

Initial infection

 * vial of serum injected by druggies
 * spread amongst druggies by reusing needles/unprotected sex
 * hospital treatment for druggies
 * blood donation for drug money
 * druggies are despicable

Outbreak

 * Bodily fluids

Reanimation

 * Must be infected before death to be reanimated
 * Cannot be reanimated if dead for too long
 * Cannot be reanimated if brain is damaged

Physiology

 * Delayed decomposition
 * Further delayed by sustinence from 'live' fluids