Challenges in Diagnosis and Treatment of HIV-Negative Host Pulmonary Talaromyces marneffei in Non-Endemic Areas: A Case Report with a History of Pulmonary Tuberculosis

<i>Talaromyces marneffei</i> is an important opportunistic fungal pathogen closely related to acquired immunodeficiency syndrome (AIDS), and its infection is relatively rare in human immunodeficiency virus (HIV)-negative populations. Although HIV-related immunosuppression remains the main risk factor, the history of treated tuberculosis and subsequent structural lung damage may constitute an underrecognized predisposing condition in non-epidemic areas, especially in elderly patients. This report described a 69-year-old HIV-negative male pulmonary infection case from a non-endemic area of <i>T. marneffei</i>, with a history of treated pulmonary tuberculosis and residual fibrotic lesions on imaging. The patient complained of chest tightness and cough for one month and fever (temperature 38.0-38.5°C) for a week upon admission. The chest computed tomography (CT) scan observed patchy consolidation and multiple cavities in the upper lobes of both lungs, accompanied by pulmonary texture disorder and pleural adhesions and thickening. The imaging findings were difficult to distinguish from active pulmonary tuberculosis. The diagnosis of <i>T. marneffei</i> infection was confirmed through sputum culture, bronchoscopy sampling culture, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS), and metagenomics next-generation sequencing (mNGS). After diagnosis, the patient was given oral voriconazole 200 mg every 12 hours, resulting in gastrointestinal intolerance. Subsequently, the dosage was adjusted to 100 mg every 12 hours, and the gastrointestinal symptoms improved significantly. The patient was eventually discharged but subsequently lost to follow-up. The case emphasizes that among HIV-negative individuals in non-epidemic areas of <i>T. marneffei</i>, for patients with unexplained pneumonia, especially those who have a history of tuberculosis and other potential immunological impairments, the differential diagnosis approach should be broadened and modern diagnostic techniques should be actively applied. It also highlights the importance of addressing drug tolerance issues and implementing long-term follow-up management in clinical treatment.