The title of this article is conjectural.

Although this article is based on official information from the Star Wars Legends continuity, the actual name of this subject is pure conjecture.

"The disease is exceptional—it spent a millennia locked away, and when the Empire blew open its vault, it came out even deadlier. It attacks the central nervous system. Seizures and agonizing death follow in hours."
―Brenna Fash[src]

A virus was locked away in one of the Rakatan vaults on the planet Belsavis that attacked the central nervous systems of its victims, causing seizures and then death within hours. During the invasion of Belsavis, the Sith Empire unintentionally released it by breaching the containment vault, and it began to spread throughout the High Security Section. Gen'Dai were immune to the virus, but it incubated in their tissue, turning them into carriers.