Plaga

Las Plagas (from Spanish, literally meaning The Plagues) are a breed of parasitic organisms. Unlike the t-virus, which turned its victims into mindless zombies, the victims of Las Plagas (such as the Ganados and Majini) become much stronger and highly resistant to pain, while working collectively to pursue their targets. Another side effect is the loss of higher reasoning, except in select subjects (who still are unable to shake off the need to obey higher orders) and the full compliance to the Control Plaga.



History
Las Plagas were first discovered by a religious group in Europe known as "Los Illuminados" (The Enlightened Ones) in an unknown, rural region of Spain. The cult used the Plagas as a means of recruiting new members. However, the first castellan of the Salazar family opposed the cult and sealed off access to the parasites in his castle.

Centuries later, Ramon Salazar, the eighth Salazar castellan, was convinced by Osmund Saddler, the new leader of Los Illuminados, to join Los Illuminados and open the seal that concealed the Plagas. The two hired the local villagers as miners to extract the parasites.



Due to years of confinement, the Plagas parasites seemed dead. Some were later found fossilized (which at least takes hundreds of years) in the rocks below Salazar's castle. However, despite this, the Plagas were still alive at the microscopic level in spores within the fossils. The miners that were excavating the site accidentally inhaled the spores which after many years gave birth to the parasites within their bodies. Since then, Saddler was able to recreate the parasites wholly, injecting them in egg form into potential hosts.

Albert Wesker, controlling what was left of the Umbrella Corporation had tasked Ada Wong with retrieving a sample of the Plagas in order to help re-establish Umbrella after learning of the creatures via intercepted messages sent by Luis Sera. He had previously employed rogue US Special Forces operative Jack Krauser to infiltrate Saddler's inner circle but decided that Ada could achieve his aims via more direct action after it appeared that Saddler was not going to entrust Krauser in his confidence. Krauser kidnaps The President's Daughter and Leon S. Kennedy is sent to rescue her, and is reunited with Ada and Krauser. He also cooperates with Luis Sera, who was being held captive for betraying Saddler. Leon kills Ramon Salazar, and looks for Ashley on an unknown island.

Saddler kills Sera and Krauser fights Leon, but is killed by Ada. Leon finds Ashley and proceeds to kill Saddler and recover the Control Plaga, but it is taken from him by Ada at gunpoint. Leon and Ashley then escape the self-destructing island via Jet-ski.

Ada betrayed Wesker and gave him a modified Subordinate Plaga (a subordinate Plaga with some genes of the control Plaga), delivering the real sample to "The Organization". However, Wesker was not fooled by the fake and he was expecting the Agency to betray him. Although he never obtained a Control Plaga sample, Wesker was able to obtain subordinate Plaga.

Five years later, within the African country of Kijuju, Chris Redfield and Sheva Alomar soon encountered Plaga-infected villagers. These plaga were modified through intensive research to enhance their performance and make more effective B.O.W.s.

Characteristics
Las Plagas are a type of parasite which alters its host's behavior by attaching itself internally to the nervous system. The undeveloped parasite is found between the lungs, beneath the heart, where it can tap into the host's spinal cord, as a link to the rest of the nervous system. Unlike other parasites, the Plagas are a social organism, meaning that they live together in social harmony. Luis Sera postulates that they have a collective intelligence akin to a hivemind, possibly communicating via ultra high frequency sound waves.

As a Plaga grows inside a host, the host can suffer from a number of symptoms (in addition to the influence of the parasite on the host's behavior). These include, but are likely not limited to: coughing up of blood, blood flowing from the eyes, convulsions, sudden unconsciousness, hallucinations, swelling and discoloration of blood vessels, and discoloration of the iris – usually to a reddish color. The eyes of an infected person can be seen to glow in dark conditions.

The parasites also have a high adaptability rate, as they can possess other kinds of organisms besides humans. (Ramon Salazar uses Plagas-infected wolves as guard dogs in his castle.) In addition to the Ganados, Saddler and his men also created several kinds of mutant creatures such as the El Gigante; the Regeneradors/Iron Maidens; Novistadors and the U3 as a result of genetic experimentation with the parasites and human specimens.

All of the members of Los Illuminados, including Saddler himself, have Plaga parasites implanted into their bodies. However, the ones used by him and his top underlings (Bitores Mendez, Krauser and Salazar) are superior to the regular Plagas allowing their host a greater amount of independence.

Except for manifesting when sufficient trauma is induced on a host, Plagas have no true mutagenic effect on their hosts' body other than the distinctive red irises. While the Plaga infecting the Ganados and Colmillos can manifest and mutilate the body of their host, they do not actually induce any significant mutation or physiological change like Umbrella's myriad viruses do. However, certain feats by enemies in the game (such as lifting Leon into the air with one hand) suggest that the parasites can increase their hosts' strength. It is this attribute that hosts exhibit no outward sign of infestation besides discolored irises which make the Plagas such a dangerous threat, as they are much more subtle and invasive than Umbrella's viruses. The Plaga parasite does not stop their hosts from feeling pain however, unlike the t-virus zombies, since the hosts have still retained their nervous system. Rather, they give their hosts better resilience against bullet wounds.

Also of note, according to a note written by Saddler, the subject's mindset does seem to be important when choosing a host ("the Plaga reflects the conscience of the hosts") suggesting that a Plaga's control over the host can be resisted, even overcome entirely. This seems to be a reference to Sera who was a host himself before managing to remove his Plaga. This might also explain the need to kill those who refused the Plaga, as they were obviously judged to be "incompatible". It also seems to be a literal description as well, at least in the case of the control plaga. As Krauser, who preferred close combat, developed a bladed arm to suit his needs.

Another side effect viewed in those infested with plagas is an apparent biological instability. That is, they disintegrate into a black or yellow goo when killed. This is common with nearly all Plaga infested individuals, both Majini and Ganados. However, certain individuals, such as the first group of Ganados that Leon encounters, Dr Salvador, J.J., Chainsaw Majini, a particular El Gigante, the first majini encountered, minibosses, and bosses, do not disintegrate when killed. Plagas themselves also suffer the same fate upon death.

In the game, Las Plagas of the Ganados, zealots, and milita only appear where the head is. Once a Plaga is exposed, the enemy will no longer sprint towards the victim.

The Majini located within Kijuju are infected with a different type of Plaga, created through extensive research. Majini have been shown to develop strange mutations, such as tentacles within their mouths, as well as the ability to fully open their mouth/jaw to expose tendrils to attack others. It has also been shown that the Plaga within Kijuju appear to already be fully awakened, and enter via the mouth or throat, already hatched, they seem to grown inside the host of another plaga which will later put it in another possible host, eliminating the need to inject the egg. These Plaga also do not appear to be harmed by sunlight, as they appear within brightly lit areas. Some strains have also been shown to fly after leaving the host body. Despite these new modifications, they are still vulnerable to bright flashes by flash grenades (i.e. UV light).

Las Plagas forms
There are several forms of Las Plagas that appear in the game. Some may be different stages of the same organism, others are very clearly different castes.

Human-inhabiting parasites

 * A-Parasite - These Plagas are the first form of Las Plagas Leon will encounter. These Plagas are most commonly found in villagers and Saddler's militia. These Plagas wield a scythe like blade on the end of a long tentacle which they will use to slash at the player at some range. They are however the weakest of the Plagas. They also control the weaker Armadura suits.


 * B-Parasite - These Plagas are the second form of Las Plagas Leon will encounter infesting human hosts. These Plagas are often found inside the lower ranking zealots, and are the second type which control Armaduras. This version of the Plaga can extend its entire body (being the Plaga itself) towards Leon and it will devour his head—being an instant kill. Other than this move, the B-parasite is capable of no other attacks. It is upon high risk that you should ever get close to this Plaga due to its one-hit kill effect; however, it can be killed by knifing although it is highly not advised.


 * C-Parasite - These Plagas (which somewhat resemble 'Facehuggers' from the Alien franchise) mostly inhabit the higher ranking zealots and militia. They are the most durable, can spit acid over some distance and detach themselves from their host following death. They are roughly equal to the A-parasites in terms of threat while attached, and are relatively weak when detached. While detached, they have a leaping grapple which lacks an animation for attacking from the side or rear, much like the Colmillos, meaning they can only use it when directly in front of Leon. Curiously, several are encountered in the game without hosts at all. When without a host, a C-parasite will eventually die even if it has taken no damage from the player whatsoever. As they can't climb ladders, simply moving outside their immediate area is an effective means of defeating them.

Non-human plagas

 * Tentacle Plagas - This form of plaga can be found in Colmillos. These wolves bear the ability to not only use tentacles to whip Leon, they will use their tentacles at will. This means that whenever a Colmillos has engaged in combat, they will automatically trigger their Plaga infestation. This normally occurs after the Colmillos has growled at the player; however, the Colmillos also may attack before using their tentacle Plaga. More than anything though, if the player engages more than one of these Plaga infested wolves, more than likely, whichever of them that does not lunge at Leon will produce their Plaga; this ultimately means, the more Colmillos you fight at once, the higher the risk is of dealing with their Plaga form.


 * Crab Plaga - This form of The Plagas only appears within Garradors. Since they cannot attack and are visible at all times, they serve as the Garradors weak spot. This is one of the few Plagas that do not possess a form of self-defense. Even though this is true, the Garradors themselves are tough to deal with if you cannot damage the Plaga. The Crab, is upon the Garrador's back and cannot be damaged unless shot at, cut, or the use of an Incendiary grenade or a Hand grenade. If the rocket launcher is in one's possession then you will be able to instantly kill the Garrador without shooting the Crab itself, but you must at least, for certain, hit the Garrador with the rocket.


 * Leech Plagas - This type of Plaga is exclusive to two closely related creatures: the Regeneradors and Iron Maidens. They are not visible externally, being entirely contained inside the host's body, and are only visible with an infrared scope. These Plagas rebuild organic matter and must all be terminated in order to kill a Regenerador or Iron Maiden. A way to remember the Leeches are to think of a "Cross Pattern". Although the pattern is not perfect, these Leeches are in a loose pattern of a cross in all Regeneradors and Iron Maidens. Caution is to be taken when dealing with the Iron Maiden, for it can latch onto a victim and then drag them into impalement.


 * El Gigante Plaga - This gigantic Plaga, resembling a giant version of the Centipede Plaga located between the host's shoulder blades, will only emerge after sufficient amounts of damage have been inflicted on its host. It serves as the monster El Gigante's only weak point. This is another Plaga form that cannot attack Leon or Ada directly. The same type of Plaga can be found in the Gigante variant known as Ndesu, though that creature has numerous smaller versions of this Plaga located throughout its body.


 * Del Lago Plaga - The plaga-infested salamander Del Lago hosted Plaga parasites similar to those found in Colmillos, filling its mouth with flailing bladed tentacles, bloating its body and grossly increasing its size.


 * Plant Plaga - The plant-like Plaga that grew within the walls of the ceremonial chamber with its giant tentacles, which then merged with Ramon Salazar and his Verdugo.


 * Modified Subordinate Plaga - These Plaga were created by the Los Illuminados researchers in an effort to combine traits of the superior Control Plaga with those of the Subordinate Plaga. In doing so, these Plaga allow the host to retain their free will, but also inherit the drastic mutative effects of the Control Plaga. These Plaga cannot control other Plagas, but also cannot be controlled themselves.


 * Control Plaga - These are complex types of Plagas. They have three distinct abilities which separates them from Subordinate Plagas; they allow the host to retain their free will, control other Plagas and cause dramatic mutations in their host at will. They are opposite of the Subordinate Plaga, and allow the host to exert complete control over the parasite. The only known subjects to have ever been infected with this Plaga were Bitores Mendez, Jack Krauser, Ramon Salazar, and Ricardo Irving . Notably, this type of Plaga can create extremely powerful individuals, while having almost no detrimental effect on the host's mental capacity; something Umbrella's top virologists failed to do.

Countermeasures
If a person has become the host of the parasite, the parasite's growth can be surpressed by taking medication. However, once the Plaga has hatched, then the only way to terminate the parasite without killing the host is for them to undergo a special kind of radiation treatment. This extremely painful procedure has the possibility of impairing the host's consciousness, and may still kill the host if the Plaga has already matured into adulthood.

Luis Sera, a researcher who betrayed Saddler, helped design a machine which produced this kind of radiation after extensive research regarding how the Plagas might be removed. Leon and Ashley, who had Plagas implanted into their bodies, used the machine to eliminate the Plagas, both managing to survive the operation.

Las Plagas are also very vulnerable to bright light. They will only emerge from their hosts at night (except in The Mercenaries), and can be instantly killed by throwing a Flash Grenade at them (except for Spider Plagas that are attached to a host; with these, a flash grenade will dislodge them from their host, while it takes a second to kill them).

Also, a weapon called the Plaga Removal Laser 412 (P.R.L. 412), which is unlockable after completion of the Professional difficulty, can instantly kill any enemy infected with Las Plagas. It is presumably a weaponized version of Luis's machine.

The kind of radiation the Plagas are weak to seems to be UV light, since most lights used to destroy it are coloured blue/purple, which means that it emits enough UV light, the sun emits UV light but most of it is stopped by the ozone layer, so the plagas are extremely weak to it. The other way to explain their photosensitivity is that they may react to a certain level of Candela (meaning that the brighter something is, the stronger it is against Plagas).

Trivia

 * The Las Plagas might have been a reference to the Pod People from the "Invasion of the Body Snatchers", because the Pod People takes control of their host's body and socialize with other infected hosts, much like what the Plagas does.
 * All lower level ganados are shown to have lost their need for personal hygeine, due to the observations Leon makes in the first few chapters of the game and various water sources throughout the game.