High Quality Content by WIKIPEDIA articles! Typhus is any of several similar diseases caused by Rickettsiae. The name comes from the Greek typhos meaning smoky or hazy, describing the state of mind of those affected with typhus. The causative organism Rickettsia is an obligate parasite and cannot survive for long outside living cells. Typhus should not be confused with typhoid fever, as the diseases are unrelated. The first reliable description of the disease appears during the Spanish siege of Moorish Granada in 1489. These accounts include descriptions of fever and red spots over arms, back and chest, progressing to delirium, gangrenous sores, and the stink of rotting flesh. During the siege, the Spaniards lost 3,000 men to enemy action but an additional 17,000 died of typhus.