A case of Rickettsia felis caused pneumonia and diagnosed by clinical analysis and Targeted Next-Generation Sequencing (tNGS) using Bronchoalveolar Lavage Fluid (BALF): A case report and literature review.

Feline rickettsia pneumonia is a rare lung disease caused by feline R. felis infection, which is mainly transmitted by feline fleas. A 57-year-old male patient was hospitalized with pain in the back of the sternum. Chest CT showed bilateral diffuse interstitial lung disease with multiple nodules. After the empirical anti-infection treatment was ineffective, the second-generation meta-genome sequencing (mNGS) of bronchoalveolar lavage (BALF) was diagnosed as feline rickettsia infection. In terms of treatment, inject tegacycline intravenously and then sequentially take minocycline. The patient's symptoms were relieved quickly, and the imaging improved significantly. This report summarizes the clinical and imaging characteristics and diagnosis and treatment experience of the case, aiming to provide reference for the early identification and treatment of such rare infections.