Green Flu, otherwise known simply as The Infection, is a contagious disease of unknown origin. It is the source of all the infected seen in Left 4 Dead and Left 4 Dead 2.
Background[]
Many have speculated the origins of this virus, as being apart of a conspiracy caused by the government, as well as apart of an alien plot or even and act of god. Within the first week of the outbreak, the virus had infected its patient zero, following being possibly living amongst livestock for sometime, leading to several people and animals within poor rural areas to begin disappearing. Many people believed it to be a new strain of flu and the Civil Emergency and Defense Agency begins informing people on how to avoid infection, which is likely when infected began their attack on the populace. Local law enforcement and CEDA would then begin quarantining areas like houses, stores and apartments, all throughout Fairfield, Whitney County, Newburg, Rayford and New Orleans, while the government began passing out masks in order to prevent the spread of the infection. Not long after, law enforcement began quarantining entire streets, setting up barricades, with patrol guards guarding them, while CEDA began distributing instructions on how to construct saferooms, which were made in basements, apartments and houses via concerned citizens. It's then that due to people trying to flee Fairfield, that there are major car accidents and fires widespread.
By the second week, Fairfield airport is quarantined, while CEDA sets up evacuation points via buses and helicopters. Airports in Savannah and Newburg are then quarantined, leading to the US military sending a small force to Fairfield, as a way to secure the city, resulting in a failed mission and all soldiers killed in action. In order the contain the infection in Fairfield, the military sets up barricades at key bridges and highways, keeping civilians and infected individuals in the city. Survivors in the city begin fortifying locations such as the hospital roof, an apartment roof, supermarket and even a generator room. It's then that helicopter pilots begin volunteering in clearing the city of civilians and by this time, the state of Pennsylvania is already overrun with infected. It's then by the end of the second week that special infected begin to appear, resulting in mutations within the virus and also the evacuation of survivors at Mercy Hospital. The helicopter however, crashes within the industrial outskirts of the city.
Into the 3rd week, it can be assumed that the military began bombing airports and other hubs of transport in order to slow the spread of the infection, as well as Millhaven military outposts become overrun by infected, due to hordes being alerted by the sound of the alarm. Georgia is then hit, where Rayford and Savannah are located and further mutations are said to be witnessed, which began appearing in the south of the country. It's said that due to failing their duties to stop the infection, the military began taking over CEDA outposts and Veterans Memorial Bridge is destroyed to slow the spread of infection, which was a direct result of New Orleans being officially declared lost.
Biology[]
In terms of biohazard containment, the Green Flu is considered the worst case scenario virus, which is level 4. Most viruses typically mutate over a specific amount of time, in order to better adapt, however this is not the case with the Flu. The flu is constantly mutating and changing and at a more accelerated rate than the typical virus and mutates every 24 hours. This allows it to be contracted a variety of ways, including airborne, waterborne and possibly, even through bodily fluids. The flu is said to be a virus, similar to that of rabies, however those it comes in contact with, typically are turned into highly aggressive and homicidal zombie-like beings, simply referred to as the infected. With most viruses, the Green Flu is no exception to rare instances of immunity, regardless if whether or not the immune are infected with the contagion. Those who are allegedly "Immune" were later revealed to be simply asymptomatic, showing no symptoms of the virus, but because they are infected, makes them "carriers", indicating they can pass it to others, albeit unintentionally. It is speculated that special mutations are linked via specific factors, such as the host's sex, influence from biochemical or genetics, as well as possibly other strains of the virus itself.
The Infected[]
Common Infected[]
While a small portion of the population are incapable of being affected by the virus, the majority who are however, are turned into what are commonly referred to as the infected. A majority of the populace that are infected, typically show minimal change from what they were as humans, however are much more aggressive, with no reasoning power and attack in massive swarms. They typically have death-like pale skin, with yellow eyes and barely visible pupils and irises. They also have no need of food or water, don't regulate their body temperature and even show no signs of fatigue. To the infected, uninfected people are seen as monsters in their eyes, which explains why they are so hostile to survivors.
Special Infected[]
While the common infected make up most of their ranks, there are those that are of the more special variety as well. Unlike the typical infected, this variant possesses specific abilities, unique to each other. They are typically a lot stronger and most won't attack head on, typically allowing their prey to come to them before engaging.
- Smoker: Smokers are a special variant of infected, which are believed to have been once heavy smokers, possessing massive growths on one side of their body, likely indicating malignant tumors and an extremely long tongue. It typically works out of sight from enemy combatants and uses it's long tongue to squeeze its victims once it's obtained it. Once killed, they will emit a massive cloud of smoke, which causes survivors to begin choking.
- Hunter: Hunters are a variant of infected, possessing superior physical strength, as well as agility. They typically pounce on opponents from great distances and claw at survivors that they've pinned down.
- Jockey: A variant similar to the Hunter, the Jockey is believed to have been once a person paralyzed from the waste down, but the virus likely restored the spinal cord function, allowing it to move. These creatures typically leap onto a target and steer them in certain directions.
- Tank: Arguably the strongest infected in the whole roster of special infected, tanks are likely the result of performance enhanced bodybuilders, using things like human growth hormones, anabolic steroids and even creatine. They are capable of feats of superhuman strength and endurance, allowing them to take multiple wounds before dying and easily capable of throwing large stones at enemy combatants.
- Charger: While similar to a tank, it's believed that the charger was once a human, who used steroids as an anti-inflammatory remedy for a growth or rash on one part of its body. It's possible that it's also attributed to gigantism, however it's inconclusive. These infected are capable of charging at survivors and pin one, while sending the rest flying. They are durable, but not to the extent as the Tank.
- Boomer: An extremely bloated victim of the virus, boomers are a variant that are capable of both producing and projecting bile at survivors. This bile acts as an attractant for the horde, which survivors are capable of taking advantage of, by collecting it and tossing it at specific locations to lure out infected. They also attack at close range, but when they die, they typically explode as well.
- Spitter: Another variant of ranged infected, spitters are capable of projecting balls of mutated stomach acid at survivors. The splash and impact, typically leaves a pool of the corrosive material, which causes damage to those standing within it. They also claw, but when they die, they typically also produce a large pool of acid.
- Witch: Considered extremely volatile, a Witch is believed to have been a victim of the virus, with pre-existing mental disorders or developed them later into the apocalypse. Where as most infected will attack on sight, witches are typically passive unless provoked and are always crying, giving the survivors the advantage in terms of avoiding it. If provoked however, witches become highly aggressive and are capable of running towards targets, faster than the survivors can move and can easily incapacitate with one hit. They have unnaturally long fingers or claws, which are able to easily break through a metal door and can take multiple hits before being taken out.