Case Report: Pulmonary tuberculosis with pneumocystis jirovecii colonization in a non-HIV patient: a cautionary tale...

The diagnosis and treatment process of this case highlights that mNGS, as a powerful pathogen detection tool, provides a rapid method for the early detection of Pneumocystis jirovecii. However, mNGS testing of lavage specimens alone cannot distinguish between colonization and infection by the pathogen, particularly when a high number of sequences are present. Clinicians should therefore interpret laboratory results with caution to avoid unnecessary treatment that may cause adverse effects to the patient. CT scans offer strong evidence for differentiating between Pneumocystis jirovecii infection and/or Mycobacterium tuberculosis infection. Performing a biopsy at the site of infection, collecting pathological samples, and submitting them for mNGS testing can further assist clinicians in making a definitive diagnosis.