A Double Pathogen Strike: A Case Report of COVID-19 and Talaromycosis Co-infection in a Patient with Post-Tuberculosis Lung Disease

An 80 year-old woman in rural Guangxi with past pulmonary tuberculosis presented for pneumonia. A month earlier, she consumed raw rodent meat, a known risk factor for Talaromyces marneffei. Post-TB structural damage with new bilateral tree-in-bud opacities on HRCT. T was confirmed after negative AFB smears, metagenomic NGS of BAL fluid. SARS-CoV-2 (35,269 reads) and marneffei (224,752 reads), despite a normal CD4 + count and negative HIV. Nirmatrelvir-ritonavir and antifungal therapy showed improvement. This scenario reveals how helpful mNGS can be for co-infections in hosts whose immune systems are competent and who have a structural lung condition—if the usual diagnostic techniques are failing.