Abstract
Pulmonary fungal infections caused by filamentous fungi of a genus Mucormycetes (formerly Zygomycetes) are a risk usually in immunocompromised patients, including those with COVID-19. Contributing risk factors are mainly diabetes mellitus and corticosteroid therapy.
The dominant species Rhizopus and Mucor form broad, hyaline, non-septate or sparsely septate hyphae in the tissue, with a wide branching angle. The angioinvasion results in thrombosis followed by tissue necrosis.
Diagnosis of the pulmonary form of mucormycosis is based on clinical examination, imaging methods, biopsy samples and cultivation examination. Fluorescence microscopy and histopathological examination of the material with specific staining (Grocott and PAS) are particularly profitable.
PCR methods have recently also been applied. Therapy of mucormycosis consists of the administration of antifungal drugs (amphotericin B or isavuconazole) and surgical debridement of the affected tissues.
Despite all advances in diagnosis and therapy, mortality still remains very high. In the case report, we describe the case of a 35-year-old man with type 1 diabetes.
He developed COVID-19 pneumonia with severe hypoxemic lung failure with subsequent infectious complications. Mycological examination of sputum by immunofluorescence microscopy revealed pulmonary mucormycosis.
Antifungal therapy with isavuconazole (approved by EMA 2015) was initiated. Subsequently the diagnosis was confirmed using the NGS (Next-Generation Sequencing) with the detection of Rhizopus microsporus.
After a temporary improvement of the condition, complications occurred due to further invasive spread of mycotic infection in the right upper lung lob and associated severe bleeding from the deposit endobronchially. It was initially treated bronchoscopically, with ongoing administration of isavuconazole.
Right upper lobectomy was successful, but later a refractory septic shock of unknown origin with multiple organ failure occurred and the patient died. Histopathological findings from the necropsy of the right lung confirmed mucormycosis.