Top 10 Video Game Diseases, Viruses, & Parasites

Cardiovascular-diseaseAn article I’ve been wanting to do for a while.  Originally, I was going to cover only diseases, but, after doing research, I found that a lot of the most popular and most interesting entries had a larger scope than that, so, instead, I switched it to covering the top 10 video game diseases, viruses, and parasites.  These aren’t meant to be in any particular order.  It’s not a countdown, nor is it meant to convey what are the end-all-be-all best entries according to public opinion.  At the same time, I have not played all of the games included in the lineup and did account for popular regard in choosing them for the article.  These are afflictions that have either made a name for themselves in the public eye, or are interesting and instrumental enough to their own stories that I believed they deserved a spot.  Hopefully you’ve heard of a few of them.

If you’ve been playing video games for any substantial length of time, I’m sure you have.

Megaman X – The Maverick Virus

Meet Sigma. I hate this man. With fervor.

Meet Sigma. I hate this man. With fervor.

If Reploid or Mechalinoid robots ever become a threat towards humanity or other Reploids, they are labelled “Mavericks.”  This can be due to programming errors or complications, the “Maverick Virus,” or just the Reploid deciding with their own free-will that they are superior and that other lifeforms should either be ignored or destroyed.  In lieu with our focus, we’ll be looking primarily at the computer-centered Maverick Virus, which causes malfunctions within the Reploid’s “Suffering Circuit,” exaggerating their irrationality or volatility.

After antagonist Sigma fuses with the virus, he re-canons it as the Sigma Virus, though all of its functions remain the same.  Sigma is then able to manipulate infected Reploids into believing that humans and human-serving Reploids are nothing more than a barrier to be overcome and are limiting the potential of the Mavericks.  Perhaps the most frightening part of the Maverick/Sigma virus is its inability to be cured.  Once infected, the victim has corrupted data and cannot be restored or returned to default settings.  Until a much later development in the series provided a cure, the one and only way to relieve Mavericks of their fatal condition was by thorough annihilation.

Pokemon – Pokerus


Note the contents of the little purple box.

One of the only benevolent entries on the list, the Pokerus is a virus that can infect Pokemon.  It cannot be healed by any medical means and may be spread from one Pokemon to the next, though the secondarily infected only keeps the benefit for a couple of days.  During its time of infection, the Pokemon is able to earn double Effort Values from the opponents it defeats, exponentially increasing its growth rate.  Pokerus has approximately a 1 in 21,845 chance of being within a found Pokemon, whether wild or bred, making it over twice as rare as finding a Shiny Pokemon.  The only way to know if a Pokemon has this condition is to check its status and look for it under the “status effects” section.  Infected Pokemon who have developed antibodies against the virus and no longer possess its effects are unable to pass along the infection.  Because of its obscene rarity and positive consequences, Pokerus is basically a holy grail in the Pokemon universe and fandom.

Warcraft III – Plague of Undeath

Check this thing out. This is the Crypt Lord. He's not very nice.

Check this thing out. This is the Crypt Lord. He’s not very nice.

The Plague of Undeath is less of a virus or other form of microscopic organism, and more of a magical affliction masquerading as a disease.  It was created by the Lich King in order to generate the Scourge, which would act as his army.  The disease is manipulated purely through the Lich King’s will, and, once spread, it kills the victim and reanimates the body under control of the Lich King.  An entire cult was created for the express purpose of accelerating the spread of the Plague overseas, known as “The Cult of the Damned.”

Many argue that the Plague, while magical, is largely fungal in nature.  The infected specimens are subject to fungal metamorphosis and some evolutionary strains of the Plague have even undergone genetic changes, altering their natural size.  This applies not only to various fauna, but also to flora.

While the current undead could not be saved, there was once a cure for the Plague, and it was brought forth only by the unified efforts of the Alliance and the Horde.

Resident Evil – The T-Virus

In case you've been out of touch with media for the last few decades, this is a zombie. Ain't it purdy?

In case you’ve been out of touch with media for the last few decades, this is a zombie. Ain’t it purdy?

Perhaps the most notorious virus on the list.  With a long history and several sub-strains, the T-Virus is manufactured, experimented with, and sold on the black market via industrial monolith, the Umbrella Corporation.  Most notable research and utilization involves the virus’s capacity to function as a bioweapon and its ability to manifest itself in almost indefinite forms on nearly every type of organic life.

To outline every detail of the virus’s actions and life-cycle would take too long, so here is a brief summary.  The T-Virus eliminates mitochondrial organelles and substitutes itself in their place.  It then works with other cells to power the body while it breaks down certain areas, leaving mostly just the motor neurons and lower brain functions in tact.  Because of the biological paradigm shift within the reanimated host’s body, the natural instinct to replenish its own lost energy and nutrients without sacrificing its own tissue becomes paramount.  This leads to the reanimated host behaving in such a way that they appear like zombies to any onlookers.  This mode of behavior, combined with the T-Virus’s general depletion of the infected’s body, creates the source material for the most infamous undead franchise in videogaming.

For a far, far more elaborate explanation of how the T-Virus would supposedly work on a scientific and neurological level, refer to the official wikia.  It’s fascinatingly accurate in its fiction.

The Elder Scrolls – Sanguinare Vampiris (Vampirism)

In this massive fantasy world, there’s more than a share of diseases the player can contract, some for their betterment, but most for their suffering.  Sanguinare Vampiris (or just, Vampirism) is the ultimate double-edged sword among these diseases.  It may be contracted in a variety of ways, most noteworthy being through assault by already infected vampiric humans.  Once the disease sets in, a short amount of symptom-free time passes, but eventually your character cannot fight it off any longer and the ultimate transformation sets in, giving way to its numerous strengths, weaknesses, and social stigmas.


“Your soul is my playground. And we don’t have any teeter-totters.”

In its early stages, vampirism is relatively harmless.  You are not burned by the sun, the vampiric traits are not prominent enough in your character to frighten others away, and your stats are only slightly above normal.  But if you go without indulging the craving for human blood for a while, the effects begin to magnify.  With each passing day, the sun will become more of a burden, until eventually you cannot go into sunlight for more than a few seconds without burning to death.  The public will label you a menace and the city guard will uniformly decide you must be removed at all costs.  In turn, some social circles will actually prefer your nonconforming ways, and the physical benefits of your supernatural state are all ramped up by several degrees.  Health, magic, and stamina all receive tremendous increases, granting you nearly god-like formidability in the deepest reaches of the disease.  Other less conventional abilities are granted as well, including vampire-specific spells.

Cures for Vampirism lie all over the Elder Scrolls universe for those who want them, though some are easier to obtain than others.  It’s all a matter of whether you want to live with the burden of being a social pariah, and if the benefits of your power are actually worth the trouble.

Mass Effect – The Genophage

The Genophage was developed by the Salarians as a weapon to cause universal genocide of the Krogans.  However, it was intended to be nothing more than a deterrent, as its possible effects were believed to be enough to keep the peace.  However, the Turians, in wanting to destroy the Krogans, employed the Genophage immediately upon its completion. The Genophage operates under the principle of reducing the number of viable pregnancies within females of that race.  Between Krogan’s natural difficulty in carrying children to term and the influence of this new pseudo-sterilizing agent, the Krogans became a race doomed to suffer defeat in a war of attrition.  Their species could not reproduce quickly enough.  That, coupled with Krogan’s natural volatility and desire to fight, brought their race to the edge of extinction.


I can haz luv, too…

If ever a female Krogan was found capable of consistently carrying offspring to term, she would become a subject of supreme importance, worthy of waging entire wars over.  Naturally, this only made the problem worse.  One female warlord used her fertility as a sort of provocation to bring the strongest males into her army’s ranks.  Knowing that their species was doomed spawned an exaggerated sense of fatalism and recklessness among Krogan’s, making them very dangerous opponents with no regard for who they attacked or what risks they took.

Lacking in scientific prowess themselves, and unable to formulate their own vaccine, the Krogan’s are therefore in a waiting game, waiting for the day that the last of their kind is to die.  Or until the Salarians manufacture and distribute a cure.

Don’t hold your breath.

Halo – The Flood

One single Flood spore can destroy a species.” – Rtas ‘Vadum, Halo 3


“We’re evil…”

A species of highly virulent, parasitic organisms that make their living and evolution by consuming sentient lifeforms that satisfy a minimum threshold of biomass and cognitive ability.  The Flood are considered to be the greatest threat to all of life and biodiversity in the entire galaxy.  The Flood are basically a giant revenge fantasy of the Precursor race, which was driven to the edge of extinction by the Forerunners.  They are also the reason the twelve Halo arrays were created, so as to purge all sentient life from the galaxy.  Apparently the Forerunners thought the Flood to be so adaptable, resilient, and powerful, that it was better to terminate all life, including their own, than let the parasite live on.


“…And we’re everywhere.”

The Flood operate under two primary stages.  First is the Feral Stage, in which the parasite will dedicate all of its drones to spreading and infecting any and all organisms that fit the bill, with no real direction.  However, once an infected member is decidedly more authoritative than the rest, it begins the process of transforming into a “Gravemind,” which takes all of the assimilated consciences and intelligence of the infected organisms to create a cohesive, strategic master for the Flood.  The generation of this Gravemind begins the Coordinated Stage, a level far more deadly than the last, as the Flood troops can be organized and given purpose to their actions, which is ultimately domination over everything.

World of Warcraft – Corrupted Blood

Those grey things? Those are skeletons. Of players.

Those grey things? Those are skeletons. Of players.

Made popular because of one particular in-game occurrence, the “Corrupted Blood Incident,” this disease had such real-world impact that it drew the attention of epidemiologists and anti-terrorism officials.  Beginning on September 13, 2005, the Corrupted Blood Incident lasted for an entire week, running amok through the universe of WoW.  It started with the attack from a boss monster, which had a damaging and highly infectious effect, allowing the attack to bounce from player to player to deal damage over time.  However, in designing the battle, there was a bug that wasn’t accounted for.  While the human players were supposed to be free from the affliction after the course of the fight, the programmers had failed to design it so the pets and minions of those players would be free as well.  This led to the animals getting out into the realms of Azeroth and rapidly infecting every player and player-partner in sight.  Lower-level characters were quickly killed and higher-level characters were righteously irritated.  The presence of the virus was so powerful that it changed how players interacted with the game, so far as to make them stay away from cities, and for programmers to initiate massive quarantines for the infected.

Eventually, the disease (which had claimed the lives of millions) was alleviated through a variety of software patches and hard resets of the game.  While it may have been accidental at first, some people would maliciously and intentionally spread the plague, and thus be labelled as the first terroristic threats in World of Warcraft.  Various professionals look to this event as a way to understand human interaction, behavior, and problem solving in the case that a similar situation should occur in our non-virtual world.

Tales of Symphonia – Angel Toxicosis



Easily one of the most fascinating story elements of Tales of Symphonia is Colette’s gradual transformation into an angel.  As the narrative progresses and the player unlocks magic seals spread across the continent, Colette (“The Chosen One”) gains additional angel powers and features, including brilliant, shining wings.  Her senses become increasingly more acute, being able to pick up small sounds and see grand distances.  But there is unforeseen backlash in Colette’s pious, supernatural pilgrimage, and she spends a great deal of effort keeping the negative effects hidden from her friends.  Angel Toxicosis begins by robbing the host of their hunger.  Not wanting to raise alarm, Colette eats small amounts of food to satisfy any friendly concerns, but she can’t keep anything down.  She loses the ability to taste and, to an extent, feel.  This keeps her from tasting anything, or judging whether something is hot or cold, leading to what is perhaps the most well-known scene from the game.  It worsens even further, robbing her of the important ability to feel pain, and eventually steals her voice entirely.

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Prototype – The Blacklight Virus (A.K.A. The Mercer Virus)

Perhaps the most scientifically elaborate entry on the list.  Using some of Elizabeth Greene’s blood as a catalyst, the Blacklight Virus was conceived as an evolutionary mutation that can only reproduce within the living cells of other biological organisms.

[The Virus] enters, re-purposes and changes the cell. The new cell replicates with formerly dormant non-encoding regions active, causing drastic biological changes.”―Node of Intrigue, Claude Cavillo


One of the most epic pictures of Mercer I could find.

The Blacklight Virus will activate the sleeping “junk” DNA in its hosts, modifying protein-encoding regions of the promoter introns in each cell.  Containing both the reverse transcriptase enzyme, as well as RNA, the virus hijacks and forces forgotten properties out of the attacked cells.  This often leads to malevolent consequences, with a mortality rate of 99.9% in all infected organisms due to critical organ failure or cell saturation.  But to the few subjects who withstand the transformation and reap its evolutionary consequences, they are granted numerous abilities and capacities leagues beyond contemporary mankind, including the conscious manipulation of one’s own genetic makeup.  The virus may be distributed or spread through injection, contact with bodily fluids, mass exposure, and physical contact/injury.  It’s dubbed by the general public as the “Mercer Virus” for its associations with the super-powered protagonist, Alex Mercer.

The Metroid Series – The Metroids

Yes, yes.  I know.  This is the eleventh entry in a “top ten” article.  It’s like magic.

If ever the video game community needed to point to a singular, iconic parasite in the vaults of their videogame kingdom, every finger would undoubtedly spear towards the Metroids.  They are the oldest entry on this list, and the ramifications of their existence hold so much impact that they are the titular creatures of their franchise, despite not being the main protagonists or antagonists in said franchise.


I wonder what would happen if you, like, ATE one of them… O_o

The Metroids were created to be a natural predator of the X Parasite, and, as a result, became the top of the food chain nearly everywhere in the universe.  They undergo various adaptations and evolutions depending on the nature of the world in which they reside, but on their homeworld of SR388, they maintain their most natural state.  Metroids possess three or four, raspberry-shaped, quadripartite/tripartite nuclei within a gelatinous, globular membrane, and a dual-set of mandibles for grasping their prey and draining their “life energy.”  This life energy is presumed to be nothing biological, such as blood, but the vague force sustaining life itself.

Metroids have no natural predators, possess extraordinary intelligence, are invulnerable to nearly every form of weaponry (biological or synthetic), and can divide asexually.  Once attached to a host, the Metroid does a swift job of draining all the prey’s life force within a few seconds.  Protagonist Samus Aran is one of the only known entities that can dislodge a Metroid, which may be accomplished by entering her Ball Form to blow it away.  Even still, this merely makes the Metroid detach and does no harm to the creature.  While Samus eventually discovers a number of other very specific, technical ways of destroying the creatures, the only reliable method is through freezing them, at which point their membrane may be shattered, but only by tremendous concussive forces on par with missile fire.  Because of her ability to do this, combined with the Metroid’s natural intelligence, Metroids will dedicate all of their effort to eliminating Samus, regardless of any other foes in their vicinity, as she is their most dangerous enemy.

The Metroids have no apparent goal besides elimination of the X-Parasite, evolving into their alpha stages, and creating more offspring. The Queen Metroid is capable of reproducing naturally, and thus must also be destroyed if there were ever hope of ultimately exterminating the parasitic race.  But, even then, few people want to completely annihilate the Metroids, as that would give rise to an influx of X-Parasites, which are also incredibly dangerous.

The Metroids are a necessary evil, which despite Samus’s efforts, never seem to stay dead.


And that’s it.  Please comment if you think there are any ailments or infections you thought were better suited to go on the list.  I’m always interested to hear back from you on these things.

God bless, keep healthy, and always remember to smile.

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VERSE OF THE DAY – John 3:16

“For God so loved the world that He gave His one and only Son, that whoever believes in Him shall not perish, but have eternal life.”

SONG OF THE DAY – “I’m So Sick” by Flyleaf

Cooper D Barham

Aspiring author, marriage and family therapist, and active behavioral health technician, Cooper fills his world with God, music, videogames, anime/manga, drawing, reading, writing, and some physical stuff in between. If you ever want to talk about the big or little things of life, fire him a message. Helping others through tough times is both his passion and way of living. 'Got it memorized?'


  1. Grayson Harvey on March 4, 2015 at 5:44 pm

    Wait. No FOXDIE?

    • Maurice Pogue on March 30, 2015 at 3:02 pm

      Yeah, that’s a pretty big MISS!

  2. Maurice Pogue on February 27, 2015 at 10:56 am

    I came for GUILT in Trauma Center or the Rosalia Virus from Trauma Team.

    I am disappoint.

    • Cooper D Barham on February 28, 2015 at 2:03 am

      Sorry. Never played any of the Trauma games. Are they on Steam? I might go for one next time there’s a sale now that I have a competent computer.

      • Maurice Pogue on March 30, 2015 at 3:03 pm

        No. It’s on NDS though.

  3. BlackAceZero777 on February 27, 2015 at 8:08 am

    Question though, with the Blacklight Virus, how does one withstand the transformation? I played the game, but never got real deep with the Virus. And with Colette, what happens to her?

    • Cooper D Barham on February 28, 2015 at 2:01 am

      I do not know the answer to the first question. I’m assuming it is some combination of chance and willpower. To answer the second, that would be a long and complicated response, so to keep it short (and remotely spoiler free), I’ll just say that she becomes an angel-puppet to this guy who plans on sacrificing her, then a huge battle goes down involving the fate of two worlds, the betrayal of one of your own party members, meeting and battling the god of both worlds, disrupting the balance of the universe, and ultimately being teleported to another dimension.

      Did I mention this is only half-way through the game? It’s okay though, Colette lives through all of that and returns to her human self.

  4. BlackAceZero777 on February 27, 2015 at 8:07 am

    Awesome post! Love it!!!!!

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