Infectious Disease Compendium

Orientia tsutsugamushi


Gram negative obligate intracellular coccobacillus. Many strains/serotypes. In its own genus.

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.

Spread by Leptotrombidium mites (aka chigger) bite. 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.


Tetracycline (preferred)(PubMed)) or chloramphenicol for 3 to 7 days. 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".