A Persistent Cough Misdiagnosed as Tuberculosis Revealing Pulmonary Aspergillosis: A Diagnostic Challenge in a High TB-Burden Setting

Abstract

Chronic pulmonary aspergillosis (CPA) is an underrecognized but significant complication of prior pulmonary tuberculosis (TB), particularly in high TB-burden settings where overlapping clinical and radiological features often lead to misdiagnosis. We report the case of a 42-year-old male who presented with a six-month history of persistent productive cough, hemoptysis, weight loss, and fatigue. He had previously been treated empirically for smear-negative pulmonary tuberculosis without clinical improvement. Initial investigations, including sputum acid-fast bacilli microscopy and GeneXpert MTB/RIF, were negative. Despite this, anti-tuberculous therapy was continued for four months, with worsening symptoms. Further evaluation at our facility revealed bilateral upper lobe cavitary lesions on chest imaging, with intracavitary soft tissue densities suggestive of fungal balls on high-resolution computed tomography. Microbiological analysis demonstrated Aspergillus species on sputum microscopy and culture, while serological testing showed elevated Aspergillus-specific IgG levels, confirming the diagnosis of chronic cavitary pulmonary aspergillosis. Anti-tuberculous therapy was discontinued, and the patient was commenced on oral itraconazole, resulting in significant clinical and radiological improvement over a three-month follow-up period. This case highlights the diagnostic challenge of distinguishing CPA from pulmonary TB in resource-limited, high-burden settings. It underscores the importance of considering alternative diagnoses in patients with persistent respiratory symptoms who fail to respond to standard anti-tuberculous therapy, especially in the context of negative microbiological findings. Improved access to fungal diagnostics and heightened clinical awareness are essential to reduce misdiagnosis and ensure timely, appropriate management.