The Heresy Plague
There exists a disease that, to the best knowledge those who keep track of such things, is unique to the First Kingdom of Humanity. The official name of this malady - the only name which the True Church of the Humanar authorizes healers to record in their annals - is the Rotting Plague. But within many circles, including more than a few among the ordained priests of the True Church, it is sometimes referred to as the Heresy Plague.
Transmission & Vectors
Technically, this disease is not contagious - at least not in the usual sense. It is not the disease that is transmitted from person to person, it is the heresy that Caronalyn takes exception to. As a heresy is spread downward among the clergy, Caronalyn afflicts those who, in her opinion, should know better than to accept beliefs and practices that she has so many times in the past made clear were unacceptable.