Etiologic agent of scrub typhus, transmitted by the bite of thrombiculid mite larvae. From the Latin oriens, "east" and the Japanese tsutsuga, "sickness" plus mushi, "insect." The disease was first documented in China in 313 AD and has been a frequent cause of illness in soldiers stationed in the western Pacific. In Vietnam, O. tsutsugamushi was among the most common causes of fever in soldiers.

Sources: Dorland's illustrated medical dictionary. 30th ed. Philadelphia: Saunders; 2003; Merriam-Webster's collegiate dictionary. 11th ed. Springfield (MA): Merriam-Webster Incorporated; 2003; and Raoult D. Scrub typhus. In: Mandel GL, Bennett JE, Dolin R, editors. Principles & Practice of Infectious Diseases. 6th ed. Churchill Livingstone; 2004. p. 2309-10.