From publisher blurb:
High Concept: Five new magic diseases, designed to drive plots, spice up encounters, and remind players that they live in a world where the black death is not the worst fate you can suffer (and provide some magic diseases with DCs high enough to threaten characters in the upper levels of the game).
Ashenblood: This arcane disease slowly destroys the body of the victim as it turns them into a fire elemental.
Barrow Plague: Those suffering from this disease are especially susceptible to the effects of necromancy, while those who die from it return as corporeal undead.
Fury Fever: Victims of this disease are filled with rage, attacking anyone who is not a carrier.
Green Guts: Subjects of this disease vomit up strange green slime.
Spellblains: Anyone suffering from this disease find it harder to prepare their own spells or resist the spells of others.