Invasive pulmonary aspergillosis in immunocompetent patients: a case series of three patients

Invasive pulmonary aspergillosis (IPA) is predominantly reported in immunocompromised patients and is uncommon in individuals without recognised host risk factors. Diagnosis in apparently immunocompetent patients can be challenging because clinical and radiological findings are nonspecific and respiratory cultures may be negative. We report three immunocompetent patients, a nursing student, gardener and a physiotherapy student by occupation, who developed IPA without classical immunocompromising conditions. All three presented with respiratory symptoms and pulmonary consolidation. Two patients had a halo sign on Computed tomography (CT) scan of the thorax. Bronchoalveolar lavage (BAL) galactomannan was positive in all three patients, with levels of 8.18, 2.12, and 1.43 µg/L (reference value <0.5 µg/L), respectively, despite negative respiratory cultures. CT guided and bronchoscopic lung biopsy on histopathological examination demonstrated septate fungal hyphae with acute-angle branching identified on hematoxylin–eosin staining in Case 1 and 2 and Gomori methenamine silver staining in Case 3, confirming invasive fungal disease. All patients were treated with voriconazole 200 mg twice daily for six weeks and showed clinical and radiological improvement. IPA can occur in immunocompetent patients despite the absence of recognised systemic risk factors. A high index of suspicion is required when pulmonary lesions persist despite conventional treatment. BAL galactomannan may provide useful supportive evidence, while bronchoscopic or CT-guided lung biopsy with histopathological demonstration of tissue invasion can establish the diagnosis. Overall, further studies are needed to clarify the contribution of environmental exposure and subtle host susceptibility in such patients.