Lazar's disease

Lazar's Disease was a contagious and eventually fatal disease. These victims are referred to as Lazars. It can be transported by air, but touch is a much more effective carrier. When infected, the victim becomes exhausted and confused. Eventually, they take on a pale and haggard appearance, often with disfiguring lesions, and become even more weakened. This disease can drag on, with the Lazar becoming even weaker and more sickly, until they eventually die.

Though the Doctor, Nyssa, Kari and Olvir all were in a similar situation while on Terminus, only Nyssa was infected. This may be due to a natural immunity or just luck.

Lazar's disease can be staved off with repeated doses of hydromel or cured with massive, controlled doses of radiation. The later remedy, for obvious reasons, entailed more risk to the infected person. (DW: Terminus)

Behind the Scenes

While the most obvious real-world parallel to Lazar's Disease is leprosy (both in the phonetically similar name and in the practice of isolating the infected), its treatment can be compared to cancer, which often features a treatment course that is sometimes as severe or injurious as the disease itself.