This article is a list of fictional diseases, disorders, infections, and pathogens which appear in fiction where they have a major plot or thematic importance. They may be fictional psychological disorders, magical, from mythological or fantasy settings, have evolved naturally, been genetically modified (most often created as biological weapons), or be any illness that came forth from the (ab)use of technology.
Items in this list are followed by a brief description of symptoms and other details.
Mundanes are immune to the disease, as demon pox is assumed to be caused by the interaction of demon poisons with the angelic nature of Shadowhunters.
Observe that crewman rub his leg
Last week he got the Neptune Plague
Today his joints are blue and yellow
In seven days he'll turn to Jello
And that last remaining blob I'll analyze
when he dies
This is my kind of sickness!
by John J. Lardieri
Similar to the Black Death and HIV/AIDS among Humans, the Drafa Plague bears a stigma among the Markab as a disease that the public felt was only caught by those considered sinful, immoral or unclean by Markab standards, and a punishment by their gods for committing such acts. The disease was named after an island on their homeworld where its inhabitants were wiped out by the disease, an island noted in Markab history for its decadence and immorality. The story of the island was eventually used to frighten small Markab children into behaving. Even accusing a Markab of being infected with the disease can bring shame, paranoia, fear, and an angry response from the accused, and Markab doctors would frequently certify someone's death from the disease as death by natural causes, so the family could avoid a scandal and the implied accusation that they or their family were unclean or immoral.