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Scrub typhus: Clinical features and diagnosis

Daniel J Sexton, MD
Section Editor
Stephen B Calderwood, MD
Deputy Editor
Jennifer Mitty, MD, MPH


Scrub typhus is a mite-borne infectious disease caused by Orientia tsutsugamushi (previously called Rickettsia tsutsugamushi). This disease was first described by the Chinese in the third century, but the first description of its classic features did not appear in the western literature until the end of the nineteenth century. Knowledge about scrub typhus increased dramatically during World War II due to its common occurrence in soldiers fighting on both sides in the Pacific theater.

The epidemiology, clinical features, and diagnosis of scrub typhus will be reviewed here. Treatment of this disorder is discussed separately. (See "Scrub typhus: Treatment and prevention".)


O. tsutsugamushi is a gram-negative coccobacillus that is antigenically distinct from the typhus group rickettsiae. This organism has features that are common to and distinct from other rickettsiae.

Like all rickettsiae, it cannot be propagated in cell-free media. (See "Biology of Rickettsia rickettsii infection".)

Unlike other rickettsiae, the trilaminar outer membrane of O. tsutsugamushi is unique in its morphology.

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Literature review current through: Nov 2017. | This topic last updated: Sep 26, 2016.
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