Endemic Scrub Typhus in South America

Scrub typhus is a life-threatening zoonosis caused by Orientia tsutsugamushi organisms that are transmitted by the larvae of trombiculid mites. Endemic scrub typhus was originally thought to be confined to the so called tsutsugamushi triangle within the Asia-Pacific region. In 2006, however, two individual cases were detected in the Middle East and South America, which suggested that the pathogen was present farther afield. Here, we report three autochthonous cases of scrub typhus caused by O. tsutsugamushi acquired on Chiloe Island in southern Chile, which suggests the existence of an endemic focus in South America. (Funded by the Chilean Comision Nacional de Investigacion Cientifica y Tecnologica and the Wellcome Trust.)