Mycologic Epidemiology and Antifungal Susceptibility Patterns of Otomycosis in Yaounde, Cameroon: A Cross Sectional Study Revealing Candida albicans Dorminance and Nystatin Sensitivity

Author(s): Awungafac SN, Ngando ML, Akem, ET, Tolefac PN, & Ndjolo A

Introduction: Otomycosis, or fungal otitis externa, has typically been described as fungal infection of the external auditory canal, with infrequent complications involving the middle ear. With an estimated global prevalence of 10%, a wide range of pathogens are implicated, which could have a significant impact on treatment outcomes in immunosuppressive conditions and the concurrent use of topical antibiotics/steroid preparations. Considering the limited data on this disease in Cameroon and the impact of various factors, including significant population growth and change, climate variations, and an increase in the number of patients, the epidemiology of otomycosis may have undergone substantial alterations over the years. There is therefore a need to characterize the mycologic epidemiology and susceptibility patterns for better treatment outcomes.

Objectives: We aimed to describe the mycological profiles and antifungal susceptibility patterns in patients with otomycosis in Yaounde, as well as to investigate potential factors associated with otomycosis in Cameroon.

Materials and Methods: We carried out a cross-sectional study on patient samples received between November 2020 to August 2021 in Yaounde University Teaching Hospital (CHUY) and Yaounde Central Hospital (HCY). Patients’ socio-demographic and clinical data were obtained. Samples were analyzed for their mycologic profiles using Sabouraud-chloramphenicol agar and antifungal susceptibility testing was carried out using the Disk and macrodilution in liquid mileu methods. Statistical analyses were carried out using SPSS version 23.0, and p-values <0.05 considered statistically significant. Results: The following fungi were isolated: Candida albicans (38%), Aspergillus niger (26%), Candida spp (22%), and Aspergillus fumigatus (14%). Nystatin demonstrated high sensitivity to most tested microorganisms, with 86% exhibiting sensitivity. Swimming and excessive ear cleaning were identified as the only two factors associated with otomycosis.

Conclusion: The most predominant fungus isolated was Candida albicans. Nystatin exhibited the highest sensitivity among other antifungals. Factors associated with otomycosis included swimming and excessive ear cleaning.