Metagenomic next-generation sequencing helped diagnose scrub typhus without eschar: A case report

Scrub typhus is caused by Orientia tsutsugamushi. Clinical manifestations include fever, rash, eschar at the bite site, and other non-specific flu-like symptoms. The eschar is a dark, scab-like area at the bite site, and is the typical lesions that prompts a diagnosis of O. tsutsugamushi. Without eschar lesions, it is difficult to identify scrub typhus. However, metagenomic next-generation sequencing (mNGS) can be used to identify infections, and this novel method may help improve clinical diagnosis.

Here, we report a case of scrub typhus in a 51-year-old woman who presented to the emergency department with a week-long fever from an unknown cause. We used mNGS to search for an infectious etiology, and the mNGS suggested O. tsutsugamushi, which was unexpectedly detected.

This study suggests that mNGS may be a useful diagnostic tool to identify clinical, causative pathogens in fever, particular ones with atypical features.