Patient Zero 

Patient Zero is the first human infected by a new or recently discovered viral or bacterial outbreak. They usually have the most basic, least mutated form of the disease, which may either make them invaluable to medical efforts or completely useless. They can also often be used to determine where the disease came from.

Becky in Contagion was Patient Zero

Patient Zero by Snowskeeper April 3, 2013

Patient Zero 

In work or educational organizations the first person in the organization with a contagious disease who winds up infecting over half of his or her colleagues.

With this year’s office cold, Sammy was patient zero.

Patient Zero by jesster79 January 9, 2020

Patient Zero 

The 1st person infected by a zombie plague starting the zombie apocalypse/end of times. reffering to a mass infection of a populace either by a secret operation or misshap. This "zombie plague" swamps normal military and law enforcement organizations, leading to the panicked collapse of civilian society until only isolated pockets of survivors remain, scavenging for food and supplies in a world reduced to a pre-industrial hostile wilderness also known as Z day.

becky was the first infected with the virus...she's patient zero. lets kill that bitch.

see:Night of the living dead, zombieland, left for dead, 28 days later

The most effective way to contain the rise of the undead is to hit hard and hit often.

Patient Zero by iheartgravediggers January 23, 2011

Patient Zero 

That unknown mysterious colleague who comes into the office, sneezes every 5 mins, spreads a ton of nasty ass bacteria that eventually has half the office calling in sick the following day.

Matt: Geez Alice, you have been chain sneezing for the last 15 mins, Are you okay?
Alice: So did you last week asshole and now everyone has gotten infected with your shit.
Matt: Yeah Bitch, I'm Patient Zero so don't fuck with me, when you see me, wear a fucking gas mask .
Alice. Off you contagious fuck.

Patient Zero by methradeth October 10, 2019

Patient Zero 

Typically an asshole that spends between five and ten minutes talking to you before mentioning casually that he/she is sick. Causing you to wonder if you've now been infected by what this mouth breathing fuck stick has. Usually its just the common cold, but it could just as easily be ebola.

I can't come in today, fuckin' Patient Zero there got me sick yesterday when he was breathing all over the coffee cups."

Patient Zero by Creeping Gibs April 26, 2009

Patient Zero Day 

As "Patient Zero" refers to the first known infected case in a zombie plague, Patient Zero Day is the celebration of the coming of the first ever zombie- that zombie is Jesus Christ. (Patient Zero Day is Easter).

"Happy Patient Zero Day! Did the bunny give you chocolate eggs?"

Patient Zero Day by seepyseedy March 31, 2013

PatientZERO_Live 

a very cool epic streamer person

hey have you seen PatientZERO_Live on twitch?

PatientZERO_Live by cl0v3rify September 10, 2021