A 69-year-old male with a history of aortic valve replacement presented with persistent fevers, weight loss, and diffuse arthralgias, indicative of a disseminated infection. Initial blood cultures were negative, and extensive workup was unrevealing. Diagnosis of disseminated Mycobacterium intracellulare subsp. chimaera infective endocarditis was significantly delayed, eventually confirmed using cell-free metagenomic next-generation sequencing (cf-mNGS) from plasma. This advanced diagnostic tool identified the pathogen after conventional methods failed, highlighting its utility in complex, culture-negative cases. The patient subsequently received appropriate antimicrobial therapy.
Key note: Cell-free metagenomic next-generation sequencing can be crucial for diagnosing culture-negative, disseminated infections, especially in cases of Nontuberculous Mycobacteria.