Level 6 DiseaseMoontusk Fever

Stage 0: The target recovers from the disease.
Stage 1: Initial Effect: The target takes a -2 penalty to saving throws while bloodied.
Stage 2: While bloodied, the target can roll only one saving throw at the end of its turn, even if it is affected by multiple effects.
Stage 3: Final State: When the subject rolls a saving throw while bloodied, it rolls two dice and takes the lower of the two results.
Check: At the end of each extended rest, the target makes an Endurance check if it is at stage 1 or 2.
11 or lower: The stage of the disease increases by one.
12-16: No Change
17 or higher: The stage of the disease decreases by one.

Published in Monster Manual 2, page(s) 158, Dungeon Magazine 181.