Invasive Fusarium rhinosinusitis in COVID-19 patients: report of three cases with successful management

Abstract

Invasive fungal rhinosinusitis (IFRS) is a life-threatening infection that can occur in immunocompromised patients, including those with COVID-19. Although Mucorales and Aspergillus species are the most common causes of IFRS, infections caused by other fungi such as Fusarium are rare. In this report, we present three cases of proven rhinosinusitis fusariosis that occurred during or after COVID-19 infection. The diagnosis was confirmed through microscopy, pathology, and culture, and species identification of the isolates was performed by DNA sequencing the entire ITS1-5.8 rRNA-ITS2 region and translation elongation factor 1-alpha (TEF-1α). Antifungal susceptibility testing was conducted according to CLSI guidelines. The causative agents were identified as Fusarium proliferatum, F. oxysporum + Aspergillus flavus, and F. solani/falciforme. Treatment involved the administration of antifungal medication and endoscopic sinus surgery to remove the affected mucosa, leading to the successful resolution of the infections. However, one patient experienced a recurrence of IFRS caused by A. flavus 15 months later. Early diagnosis and timely medical and surgical treatment are crucial in reducing mortality rates associated with invasive fusariosis. Additionally, the cautious use of corticosteroids in COVID-19 patients is highly recommended.

Keywords: COVID-19; Fusarium; antifungal susceptibility testing; immunocompromised; rhinosinusitis.

Figure 1

(A) Chest CT scan showing patchy ground-glass opacity, bilateral consolidation, and atelectatic bands. (B, C) Paranasal and orbital CT scan displaying opacification in all paranasal sinuses, destruction of medial septum in the left maxilla, bilateral retrolental fat haziness, medial extra and intraconal fat haziness, and inflammation of medial and superior rectus muscles. These findings suggest a fungal sinonasal invasion in the right orbital.

Figure 2

(A) Direct microscopic examination using 20% KOH revealing hyaline hyphae (×400). (B) Histopathologic examination with H&E staining showing infiltration of acute and chronic inflammatory cells, bleeding, and fungal hyphae (×1000). (C, D) Surface and reverse isolated colony after four days of incubation at 25°C. (E) Microscopic appearance of the isolate as observed on a slide prepared from the fungal culture (×400).

Figure 3

(A) Chest computed tomography scan demonstrating atelectasis in the right lower lobe, patchy consolidation in the left upper lobe, bilateral patchy ground-glass opacity, bilateral pleural effusion, pericardial effusion, right collapse consolidation, and air bronchogram. (B, C) Paranasal CT scan showing bilateral medial and sphenoid opacification, ethmoid destruction, medial septum destruction in the left maxilla, and bilateral frontal mucosal thickening.

Figure 4

(A) Direct microscopic examination using 20% potassium hydroxide revealed septated hyaline hyphae (×400). (B, C) Histopathologic examination with hematoxylin-eosin stain showing infiltration of inflammatory cells (PMNs), fibrinolocyte exudate, septate acute angle fungal hyphae, and conidial head (×1000). (D, F) Morphological characteristics of colonies on Sabouraud dextrose agar after four days of incubation at 25 °C. (E) Microscopic morphology of Fusarium observed at ×400 magnification.

Figure 5

(A) Chest computed tomography scan showing bilateral disseminated mixed ground glass and consolidation suggestive of COVID-19. (B) Paranasal sinuses demonstrating fibrino leukocytic exudate, necrosis, and destruction of the nasal septum. (C) Direct KOH microscopy of tissue samples revealing hyaline septate hyphae (×400). (D) Histopathological examination of tissue sections revealing necrosis, edema, bleeding, and irregular and acute angle septate hyphae (×1000). (E, F) Reverse and surface of the isolated Fusarium solani colony on Sabouraud dextrose agar after four days of incubation at 25°C. (G) Microscopic morphological characteristics of the isolate in slide culture at ×400 magnification.

Figure 6

Agarose gel electrophoresis of PCR products from DNA amplification of three Fusarium strains isolated from three patients. Amplification was performed for the translation elongation factor 1-alpha (lanes 1-3) and the entire ITS1-5.8 rRNA-ITS2 region (lanes 4-6). Lanes N and NE denote the PCR and DNA extraction controls, respectively. Lane M displays a 100 bp DNA molecular size marker.