Eurosky Low-Emission Infectious Disease, otherwise known as ELID, is an affliction which mutates any living organism that has been exposed to Collapse Fluid (CF) Radiation.
Surface areas exposed to CF radiation will suffer from a certain degree of silicification depending on the level of contamination. This radiation can contaminate weather systems, producing “Collapse Storms” and bringing wide-spread contamination.
ELID infected behave aggressive and feral to everything except its own kind. However, ELID are not risen from the dead. Infectees who turn are still living creatures.
Immediately following exposure to Collapse Fluid radiation, a subject will begin coughing blood, and experience fatigue and pain throughout the body. Radiation burns may also begin to present on any exposed flesh. In time, contamination will lead to organ failure, mental impairment, silicification of the epidermal layer and organs, difficulty breathing, unstable vital signs, abnormal metabolism, and calcification of the skeletal structure resulting in a hardness that surpasses steel.
Freshly mutated cells will not only continue their mitosis, but also produce a new cell organelle that releases Collapse Radiation. In other words, an infected organism becomes a new vector of Collapse Radiation contamination. This is why infectees are transmissive. Because of this, direct contact with a contaminated individual is dangerous even if they have not yet turned.
Increased red blood cell count and decreased white blood cell count leads to immunosuppression, preventing the immune system from fighting off the mutated cells now producing CF radiation, leading to more cells becoming mutated. This, plus environmental contamination is how mutated cells propagate. As the mutation progresses, white and red blood cell count returns to normal, but immune response is lost.
The speed and severity at which these ailments occur depends on the level of contamination in an area. It is possible for an infected subject to perish because of their symptoms without turning into an ELID creature. Individuals with strong constitutions able to withstand the symptoms will turn without receiving treatment in time.
All infected creatures are attracted to noises and movement not produced by other infected of the same kind. Because of this, it is very easy to mistakenly attract nearby roaming infected or intentionally bait them to a specific area. The infected lose their vision and retain some degree of muscle memory, moving instinctively, despite the loss of cognitive function and sight. ELID are always in an aggressive, berserk state and their feral bites, and wild flailing are deadly after being enhanced by Collapse Radiation.
ELID which remain in contaminated zones or return to them will undergo further mutations, eventually becoming malformed and nightmarish. Intense, acute exposure to Collapse Radiation can cause heightened mutation leading to an ELID creature immediately more monstrous and inhuman than infectees exposed over a longer period of time.
Examples of animals which have undergone mutation via ELID include, but are not limited to: Bears and Boars with silicated hides and protruding fangs, Deer with Antlers 4-meters tall, and Spiders of increased size which spit corrosive acid. Tests conducted on an ELID Boar revealed that 9mm bullets were ineffectual and 5.56mm caliber ammunition posed little threat to the hardened hide.
There is a single confirmed case of a subject undergoing mutation via ELID, yet not becoming deranged and retaining their senses. This individual was able to survive in Collapse contaminated environments, but showed signs of autoimmune disease and weakness in areas which were not contaminated. In time the subject would have died from autoimmune disease and organ failure.
Within contaminated zones, ELID ecosystems begin to exist. Silicated terrain and crystalline trees become a common sight and ELID creatures of different species prey upon each other.
Treatment and Protection
Little has been stated about the subject, but it is confirmed there is treatment for CF exposure if it is received within an unspecified period of time. There is no cure once an infectee has fully mutated into an ELID creature.
Protective suits are shown to exist which offer some degree of protection within a contaminated environment. Extremely high levels of CF contamination, like those found within a “Black Zone” will bypass all protection and survival is unlikely once entered. In a “Red Zone” heavy protection is required for both humans and Dolls. For a “Yellow Zone” only humans require protective gear, while Dolls do not.
A vaccine may exist which increases resistance to CF Radiation, but does not cure or prevent ELID, however, this vaccine has not been referenced in Girls' Frontline yet.
Barrier Walls constructed at great height prevent roaming ELID from getting in designated “Green Zone” areas and also help to ease the pressure of CF storm systems. Purification towers are often stationed along these walls or designed to be mobile to move along the perimeter and “cleanse” CF Radiation contamination over a period of time in their area of effect. It is unknown how these towers work, leaving the question of how the towers purify an area unanswered.