Senscontagium

When the flying stabber first contracted plent fever the fever mutated into senscontagium, a feverlike disease that infects mucous membrane, especially the ones of sensory organs. This causes headache, confusion and obviously reduced vision and sometimes causes organ failure. However, most of the time, and to most creatures, the senscontagium is not deadly, but it is spread easy, through feces and saliva. However, the flying stabber, that was the host the disease mutated in, has developed a strong immune defense against the disease and can therefore carry it without being damaged by it. This makes them dangerous hosts which spreads the disease.