Latent Tuberculosis Infection and Cryptococcus and Rhinovirus Co-Infection in an Immunosuppressed Patient

BACKGROUND: Mycobacterium tuberculosis may persist latently within the host, often presenting with atypical clinical features. In the context of immunosuppression, latent infection can reactivate, and the increased susceptibility to opportunistic infections further complicates the diagnosis and management of tuberculosis. METHODS: We report the case of a patient with connective tissue disease and a history of pulmonary nodule resection, who developed respiratory symptoms following two months of methylprednisolone therapy. The initial diagnosis was community-acquired pneumonia. Targeted next-generation sequencing of sputum identified pathogens. RESULTS: tNGS identified multiple pathogens, including Mycobacterium tuberculosis, Cryptococcus, and rhinovirus. Retrospective analysis suggested that tuberculosis likely resulted from the reactivation of latent Mycobacterium tuberculosis bacilli at the site of a previously resected pulmonary lesion. CONCLUSIONS: In immunosuppressed patients, latent tuberculosis reactivation and rare infections should be considered. When symptoms are atypical, tNGS provides an effective tool for rapid and accurate pathogen detection to guide treatment.