History Main / TyphoidMary

* World War Z had carriers' organs being harvested and sold on the black market, spreading the infection across the world.

* [[http://en.wikipedia.org/wiki/Mary_Mallon Mary Mallon]]

** Her son inherited her carrier gene, which [[{{Understatement}} ends badly]], as [[spoiler:he carries it into France, where it somehow triggers a whole new infection.]]

** Confirmed in the comics for "The Passing:" the original ''Left 4 Dead'' Survivors learn that they've been spreading the infection across the country and may have inadvertently doomed everyone who helped them in the previous campaigns.

[[AC:LiveActionTelevision]]

* Another ZombieApocalypse example is the ''DeadRising'' series: the plague was brought to America by orphaned children [[spoiler:(who, in turn, were brought to America by Carlito Reyes)]] who were infected by the viral agent, then placed in a governemt adoption program. Then, all hell broke loose, (at least) Willamette and Fortune City went to hell, and the rest is history.

* It's worth noting that it's not as uncommon as one might think for a person to be contagious, despite having few to none of the symptoms generally associated with the disease they're carrying. Overall health isn't always an indicator of how likely someone is to become a "Typhoid Mary", either. As such, that "head cold", those "allergies" or that feeling of being "a little more tired than usual" could, in fact, become a life-threatening illness for someone you pass it to (and their overall health isn't always an indicator of how likely ''this'' is, either). This is part of the reason why health departments have been pushing people to get the flu shot, especially with H1N1.

* In ''[[TwentyEightWeeksLater {{28 Weeks Later}}'', Alice is an asymptomatic carrier of the Rage virus, which results in it breaking quarantine.

* Another ZombieApocalypse example is the ''DeadRising'' series: the plague was brought to America by orphaned children [[spoiler:(who, in turn, were brought to America by Carlito Reyes)]] who were infected by the viral agent, then placed in a governemt adoption program. Then, all hell broke loose, Willamette and Fortune City went to hell and the rest is history.

* [[DeconstructedTrope Deconstructed]] in ''TheZombieHunters.'' [[ZombieInfectee The Infected]] contract TheVirus through exposure to ''any'' [[TheUndead zombie]] bodily fluids through an orifice or wound, but only being bitten or [[PoisonIsCorrosive vomited on]] causes [[ViralTransformation imminent zombification]]. Otherwise Infected can live full, asymptomatic lives, as the virus will remain dormant. However, they can infect others through their own bodily fluids, and will inevitably [[CameBackWrong reanimate]] after death. On the [[IslandBase Island]] [[PoliceState Military Base]] [[EndangeredSpecies humanity's remnants]] inhabit, Infected are both [[FantasticGhetto segregated]] from and forbidden from [[NoSexAllowed romancing]] the uninfected. Infected are also [[DystopianEdict required to]] wear [[FantasticRacism identifying armbands]] and ID tags, [[BigBrotherIsWatching pass through checkpoints]], and [[FascistsBedtime obey curfews]] while among uninfected, and the unskilled are [[FantasticCasteSystem exploited]] as [[WeHaveReserves highly-expendable]] DisasterScavengers. (The titular hunters) All residents are tested regularly, and anyone who goes off-island has to pass through quarantine and [[DecontaminationChamber decontamination]].

* [[DeconstructedTrope Deconstructed]] in ''TheZombieHunters.'' [[ZombieInfectee The Infected]] contract TheVirus through exposure to ''any'' [[TheUndead zombie]] bodily fluids through an orifice or wound, but only being bitten or [[PoisonIsCorrosive vomited on]] causes [[ViralTransformation imminent zombification]]. Otherwise Infected can live full, asymptomatic lives, as the virus will remain dormant. However, they can infect others through their own bodily fluids, and will inevitably [[CameBackWrong reanimate]] after death. On the [[IslandBase Island]] [[PoliceState Military Base]] [[EndangeredSpecies humanity's remnants]] inhabit, Infected are both [[UrbanSegregation segregated]] from and forbidden from [[NoSexAllowed romancing]] the uninfected. Infected are also [[DystopianEdict required to]] wear [[FantasticRacism identifying armbands]] and ID tags, [[BigBrotherIsWatching pass through checkpoints]], and [[FascistsBedtime obey curfews]] while among uninfected, and the unskilled are [[FantasticCasteSystem exploited]] as [[WeHaveReserves highly-expendable]] DisasterScavengers. (The titular hunters) All residents are tested regularly, and anyone who goes off-island has to pass through quarantine and [[DecontaminationChamber decontamination]].

* [[DeconstructedTrope Deconstructed]] in ''TheZombieHunters'' [[ZombieInfectee The Infected]] contract TheVirus through exposure to ''any'' [[TheUndead zombie]] bodily fluids through an orifice or wound, but only being bitten or [[PoisonIsCorrosive vomited on]] causes [[ViralTransformation imminent zombification]]. Otherwise Infected can live full, asymptomatic lives, as the virus will remain dormant. However, they can infect others through their own bodily fluids, and will inevitably [[CameBackWrong reanimate]] after death. On the [[IslandBase Island]] [[PoliceState Military Base]] [[EndangeredSpecies humanity's remnants]] inhabit, Infected are both [[UrbanSegregation segregated]] from and forbidden from [[NoSexAllowed romancing]] the uninfected. Infected are also [[DystopianEdict required to]] wear [[FantasticRacism identifying armbands]] and ID tags, [[BigBrotherIsWatching pass through checkpoints]], and [[FascistsBedtime obey curfews]] while among uninfected, and the unskilled are [[FantasticCasteSystem exploited]] as [[WeHaveReserves highly-expendable]] DisasterScavengers. (The titular hunters) All residents are tested regularly, and anyone who goes off-island has to pass through quarantine and [[DecontaminationChamber decontamination]].

* {{Zombie Infectee}}s in ''TheZombieHunters'' who are not infected through a bite can live perfectly normal lives with no symptoms, but they will turn into zombies at death and can easily infect others. For this reason, Infected have to wear special armbands and ID tags and live in fenced-off quarantine areas.

* In ''Twenty Eight Weeks Later'', Alice is an asymptomatic carrier of the Rage virus, which results in it breaking quarantine.

The Typhoid Mary is a character who carries an infectious disease. She often doesn't suffer any visible symptoms, appearing perfectly healthy to the average observer. However, the Typhoid Mary is incredibly contagious, and spreads the disease to everyone she encounters.

Unlike the {{Plaguemaster}} and PoisonousPerson, the Typhoid Mary isn't a villain. She doesn't intentionally try to spread her infection, and is often unaware that she is infected at all; she is at worst ObliviouslyEvil. However, villains may try to use the Typhoid Mary as a weapon, deliberately infecting an unsuspecting person with a contagious disease so she can unknowingly spread it to others.

In ZombieApocalypse works, there may be some overlap with the ZombieInfectee, depending on the way the zombie infection spreads. In most cases, however, the Zombie Infectee doesn't pose a danger of infecting others until he actually dies and become a zombie himself. The Typhoid Mary, on the other hand, is highly contagious from the first moment of her infection.

The TropeNamer is the RealLife example of Mary Mallon, "Typhoid Mary", a healthy carrier of typhoid fever who infected at least 53 other people, all the while refusing to believe that she was sick.

In biology this is known as a carrier.

Not to be confused with the ''{{Daredevil}}'' villain.

* It's worth noting that it's not as uncommon as one might think for a person to be contagious, despite having few to none of the symptoms generally associated with the disease they're carrying. Overall health isn't always an indicator of how likely someone is to become a "Typhoid Mary", either. As such, that "head cold", those "allergies" or that feeling of being "a little more tired than usual" could, in fact, become a life-threatening illness if you pass it along to someone else (and their overall health isn't always an indicator of how likely ''this'' is, either). This is part of the reason why health departments have been pushing people to get the flu shot.

* The vast majority of infections illnesses have some sort of incubation period, a time between the person catching the disease, and symptoms appearing. The person is rarely infections during this period (though there are some exceptions), but it does allow said oblivious infected person to go off to some new location and spread the illness there (sick persons rarely travel, limiting the spread into new areas after symptoms have appeared). Longer incubation periods, sometimes measured in weeks, when combined with today's easy long distance travel can be, shall we say, problematic, spreading unwitting sleeper agents of pandemic across the globe.

* Lenie Clark of Peter Watts' ''RiftersTrilogy'' series carries βehemoth back to the surface world.

In biology this is known as a vector. We were able to successfully eradicate smallpox in part because humans were the only vector for the disease.

* In ''ThePowerpuffGirls'', the Amoeba Boys catch a cold and cause a city wide epidemic. Although they are villains (or at least try to be), they did not spread the cold on purpose, and so are this instead of {{plague master}}s.