Challenge #03829-J177: A Bird Named Enza
All the magic users in a town are down with the sniffles. The stronger the magic, the worse they feel. Alas, even viruses can be magical. In this case, it's just another type of cold. People'll survive, it's just not comfortable. -- Anon Guest
The most common name for it was the Faekindred Flu since first it effected those whose ancestry hailed from Nanogh, the plane of magic. The local Hellkin and Hallobloods were also struck down, but prejudice rendered them less visible than the local Elves.
What alarmed most was when the local Clerics attempted to cure the disease, and immediately fell victim to the infection.
Then the same thing happened to the Druids in the area. Anyone with the slightest hint of magic fell ill. It was only those without the vaguest hint of magic in their makeup who remained in good health. Which made things very difficult.
[Check the source for the rest of the story]