The Contagion

The Contagion is a small, non-enveloped RNA virus. It replicates through binding to the cell membrane, entering the cell and using the cell’s machinery to read the RNA and make viral proteins. It has a high mutation rate, making it difficult to target via a vaccine or drug. Transmission outside of the Sanctum usually occurs through abrasion of exposed skin via caustic chemicals present in the atmosphere, permitting entry of virus present in the air (due to its size, the virus can remain airborne in tiny droplets for long periods of time.) Direct inoculation can also occur through inhaling virus-laden bodily fluids or introducing those fluids through a puncture or wound. The progression of the illness tends to be faster in cases of direct inoculation.

The virus was designed to trigger a localized, massive immune response. Most of the damage is due not to the virus harming cells itself but to it overactivating immune cells and complement pathways, which rapidly destroy cells, causing necrosis. Amputation is useful in the early stages of the disease because the infection begins superficially and the movement of the virus is impeded by the obstruction of small blood vessels by cell material. Over the course of two or three days, the virus makes its way into larger vessels and proceeds to the brain. The tissue death in that location leads to disorientation, aggression and other neurologic symptoms. Perception of pain is usually dampened. This stage may terminate within a few days with paralysis and death or continue for longer periods.

No vaccine or reliable drug therapy exists, though there are persistent rumors that individuals have survived the illness via medically induced coma or other last-resort treatments.

History
The Contagion is presumed to be an artificially created virus, developed as a biological warfare agent during the arms race that followed the Crash. It is unknown in which city the Contagion was developed, or by who. The first known infection occurred in 3137.