Giant's itch or Stone Curse

Write about a disease with an unknown origin in your world. How do people treat it?
Giant's Itch is a terrible ailment that causes most humanoids to turn to slowly turn to stone. Its origin is unknown, however there are several different tales of its creation. The way its transmitted is by touching anything that has been fully petrified by it. The dust of a Stone Cursed statue is sometimes used as a biological weapon. 
By slowly turning most humanoids into stone statues, giant's itch is a very deadly disease. The disease is spread through physical contact of either fully petrified people or their ground up remains.

Transmission & Vectors

Physical contact with any infected limbs or remains of infected people.

Symptoms

Physical symptoms upon first contact are increasing numbness and rigidness in effected area. The second stage of the illness causes the numbness to grow and spread to surrounding areas. Additionally infected people start to feel their mind growing number and become lethargic. The third stage causes the skin and muscle tissue to harden into a concrete like material losing all sensation. At this stage the growth progress accelerates and spreads faster. The mental capacity of those infected also becomes significantly reduced. If the head or neck is infected and untreated during the second stage, the infected person dies once they reach stage three. At stage three the disease becomes contagious. The rate at which the symptoms increase is based upon a persons physical wellness, ranging from 8 hours two 2 days. In very rare cases, fully infected people are able to move around and attack others to spread the diasese.

Treatment

Amputation is the primary form of treatment for Giant's itch. If amputated an inch above the contact point during stage one or two, then the growth stops. If the infected person knows they are infected within moments of contact they may be able to flay their skin off to prevent further spread. There is supposedly a way to revive someone who is fully

Prognosis

The mortality rate for the diease is

Type

Magical