Rickettsia felis Pulmonary Infection Detected via Metagenomic Next-Generation Sequencing in a Clonorchiasis Patient: A Case Report.

Rickettsia felis (R. felis) is a Gram-negative obligate intracellular bacterium with a global presence across various hosts, including mammals, humans, and ectoparasites. Herein, we present a case of R. felis infection in a previously healthy 43-year-old male with a history of Clonorchis sinensis and recent corticosteroid use. The identification of R. felis was accomplished through metagenomic next-generation sequencing (mNGS) of the patient's bronchoalveolar lavage fluid (BALF). This case represents the first documented pulmonary infection caused by R. felis in China, confirmed by mNGS analysis of bronchoalveolar lavage fluid (BALF) and reported from Shenzhen, China.