Infectious Disease Compendium



Gram negative obligate intracellular coccobacillus. Orientia tsutsugamushi and Orientia chuto (PubMed). Many strains/serotypes. In its own genus. Diagnose with serology.

Epidemiologic Risks

Found in South Pacific, Asia, Australia it is spread by a mite from wild rodents. In 2016 it made it to ChiloƩ Island in southern Chile (which may be a unique organism (PubMed). Orientia chuto in Dubai.

Spread by Leptotrombidium mites (aka chigger) bite, which are both the vector and reservoir. 6-10 day incubation.


Scrub typhus: Fever, severe headache, and myalgia; often with tender lymphadenopathy in the region of the bite followed in 5 days by rash that goes from extremities to central.


Tetracycline (preferred)(PubMed). In northern Thailand there are tetracycline resistant strains, may want to use azithromycin. And azithromycin is equal to doxycycline (PubMed).

Quinolone resistant (PubMed)(PubMed).


Due to great antigenic variability, infection does not confer resistance to other strains.

I just love to say the word "tsutusgamushi"; do not ask me why.

From Japanese tsutsuga "illness" and mushi "insect".

It was a problem in the Pacific theater in WW2 (Review)

Last update: 05/05/18