Talaromyces marneffei Infection in Non-Endemic Areas: Two Case Reports, Diagnostic Insights, and Literature Review

Talaromycosis is an invasive fungal infection caused by the pathogenic fungus Talaromyces marneffei (T. marneffei), prevalent in Southeast Asia and Southern China. This disease is rare in non-endemic areas and primarily affects the respiratory system with atypical manifestations. Therefore, the condition is often misdiagnosed as other respiratory infections. This article presents two cases of talaromycosis in non-endemic areas, aiming to provide diagnostic and therapeutic references for this rare fungal infection.

Two cases of talaromycosis in non-endemic areas were retrospectively analyzed. The first case involved a human immunodeficiency virus (HIV)-infected patient with tracheobronchial talaromycosis. Bronchoscopy revealed multiple nodular neoplasms in the trachea and bilateral main bronchi. Histopathological examination of the biopsy tissue showed histiocyte aggregation and intracellular pathogens. T. marneffei was identified by microbial culture of bronchoalveolar lavage fluid (BALF). The second case was an HIV-negative patient with pulmonary talaromycosis. Bronchoscopy revealed mucosal congestion and edema, and T. marneffei was detected by metagenomics next-generation sequencing (mNGS) of BALF.

Talaromycosis warrants more clinical attention in both HIV-negative individuals and non-endemic areas. In addition, clinicians should improve diagnostic recognition of this disease for timely management. Bronchoscopy combined with mNGS can facilitate early diagnosis of talaromycosis, particularly in culture-negative cases where conventional methods fail. This strategy directly addresses a major diagnostic challenge and improves patient prognosis.