Patient Zero

Patient Zero needs images. You can help by uploading an image and adding it.

In medicine, Patient Zero (also called the "index case") refers to the original source of an outbreak of a contagious illness within a population (that is, the origin of the outbreak from whom all other infections are ultimately derived) or to the most significant case within the population. Chandra Suresh told his son Mohinder that he believed he was close to discovering the "Patient Zero" for his theories about new human evolutionary traits. Suresh's research indicates that his identified "Patient Zero" was Sylar.

It is presently unclear in exactly what sense Dr. Suresh was using the term--that is, whether Suresh believed Sylar to be the individual whose powers emerged earliest, to be the first born of the individuals to develop powers, or even if he believed Sylar was pathologically responsible for the emergence of new genetic traits in other individuals.