"I have seen it only once, and only briefly while running away. If someone gets the bat madness, there is no shame in running away unless you have six strong men, heavy rope, sleeping draughts, and bag of milk thistle. You need all these things for even chance of saving the bat-mad, and there is no honor in dying for one who cannot be saved. Death is not stranger to we Hegyem, and I have seen many kind of death--have even dealt it by my hand, you know this--but none as terrifying as brief glimpse I saw of man doomed to die bat-mad."
Transmission & Vectors
Bat-Madness is usually transmitted by the bite of a Spite Bat, but can also be contracted by any method that introduces the venom (even in the relatively small amounts found in the blood of an infected victim) into a person's blood stream. Those who attempt to help a victim (who is bloody from all their self-inflicted wounds) can therefore become infected by the victim's blood, as can those who handle the venom when making Hulya's Breath.
Bat Madness is the name that the Hegyem have given to the condition caused by the bite of their hated foe, the Spite Bat.
Immediately after being bitten, a Spite Bat victim will feel an intense itching around the bite wound. This itch is so intense that most victims will stop whatever they're doing--even defending themselves from the Spite Bat's continued attacks--to scratch at the wound, sometimes so intensely that it causes the wound to grow. Not long after the itching begins, the victim will feel as if something malicious is moving around inside of their body; the handful of Bat Madness survivors have variously described it as "a great slithering worm," "a dozen skittering spiders," and "a demon of pure evil." As this feeling intensifies, the victim becomes so wracked by pain that the only thing they can think about it removing whatever is crawling around inside of them. The victim will use any sharp implement at hand--including teeth and nails if nothing better is available--to attempt to cut the thing out of them. As the (by all indications, imaginary) thing moves around, they will inflict more and more wounds upon themselves until they puncture an important organ or bleed to death from dozens of self-inflicted wounds.
Bat Madness can be treated by having the victim drink a tea-like concoction made with milk thistle flowers, but this is easier said than done. A bat-maddened person will violently attack anyone who attempts to interfere with their quest to be rid of their imaginary parasites, and the fear and desperation of the experience seems to heighten their strength and resistance to damage. Even knocking the victim out will only buy the would-be rescuers a brief period; the hallucinations are so strong that they seemingly affect an unconscious victim, causing the victim to fight their way back to wakefulness in a very short time. Just making the opportunity to administer the antidote requires that the victim be subdued or knocked out, given a heavy dose of sedatives, and tied down for good measure. Since anyone who attempts to save a Bat-Madness victim risks contracting the disease themselves, most are left to die unless conditions for a rescue are very favorable or the person infected is extremely important or well-liked.
Bloody, self-inflicted death. At least in most cases.
Avoid Spite Bats. Always take a Sin-Eater Goat with you when venturing into Hegyembi mines and caves.