Heatchills

Originally an elven inless, originating in the furthest south islands inhabited by the Sea Elves, this illness eventually made its way into the human population of Southsea once they were significantly integrated into each others' cultures.
While not particularly dangerous to the elves that originally contracted it, and typically only taking a few days of moderate symptoms to recover, it is often more severe in humans. While still not having an exceptionally high fatality rate, the disease that was nigh unheard of to die from began claiming human lives.
Only one or two out of every hundred that caught it, but even in the rest of cases, the symptoms were often much more severe. Sufferers feel burning hot, to the point of pain, while shivering uncontrollably. It gets so bad in many cases that it renders the sufferer incapacitated for upwards of a week before the symptoms begin to ease.
It went on this way for decades, a notable problem that would take a notable toll on Southsea for a decent portion of each year. While magic was able to help quell the illness, such spell are not easy to cast, and there aren't enough practitioners of such advanced magic in Southsea to readily cure the majority of sufferers, nevermind stamp out the illness entirely.
Eventually, however, through the combined efforts of a human alchemist and his elven cleric wife, a solution was found. It took many years of trial and effort, even after heavily researching the notes from previous attempts, but they eventually proved successful.
The cure worked, but it required ingredients that didn't grow in Southsea. This made it highly expensive, and it only helped to slow the illness slightly for several years.
However, eventually a trade route was worked out to a town further into the Midland, where the needed plants grew readily. This allowed the price of this cure to come down significantly, and over time the illness was all but completely wiped out.
The trade routes created to aid in the cure still stand, and have proved a notable source of prosperity for both parties since.

Type

Viral