A Study on the Prevalence of Fungal Isolates Among Rhinosinusitis Patients at CMCH, Coimbatore

Background and Objectives: Fungal rhinosinusitis may present as allergic disease, a non-invasive fungal ball, or infection involving the surrounding tissues. This study examined the fungal species recovered from patients with rhinosinusitis, the types of fungal disease encountered, associated clinical conditions, and antifungal susceptibility findings. Methods: This prospective hospital-based study included 106 patients with chronic rhinosinusitis who underwent diagnostic nasal endoscopy and/or functional endoscopic sinus surgery at Coimbatore Medical College Hospital. Samples were examined by potassium hydroxide microscopy, fungal culture, and histopathology. Amphotericin B minimum inhibitory concentrations (MICs) were measured by broth microdilution and Etest. Voriconazole MICs were also assessed for Aspergillus isolates. Results: Fungal rhinosinusitis was identified in 22 of 106 patients (20.8%). Of these 22 cases, 15 (68.2%) had allergic fungal rhinosinusitis, three (13.6%) had chronic invasive disease, two (9.1%) had acute invasive disease, and one each (4.5%) had a fungal ball or chronic granulomatous disease. Aspergillus flavus was the commonest isolate (11/22; 50%). KOH microscopy was positive in 21 cases and histopathology in 17. Asthma or diabetes was recorded in 15 of 22 fungal cases and 19 of 84 non-fungal cases. Conclusion: Fungal rhinosinusitis was found in about one in five patients in this selected endoscopic and surgical cohort, most often in its allergic form. Microscopy, culture, and histopathology should be interpreted together. Antifungal MIC results need careful interpretation because validated species-specific clinical breakpoints are not always available.