Clinical and Microbiological Epidemiology of Otomycosis in the Centre Region of Cameroon

Abstract

Otomycosis is a superficial, sub-acute or chronic infection of the external auditory canal, characterized by pruritis, inflammation, pain and itching commonly seen in tropical and subtropical regions of the world. Various host and environmental factors can predispose a person to otomycosis. However, a clinical presentation along with otoscopic observations of the patients shows fungal and bacterial infections. Proper identification of causative agents is necessary in order to prevent recurrences and complications such as hearing lost. The aim of our study was to determine the fungi and bacteria pathogens causing otomycosis and to derive association of risk factors with otomycosis of the clinically diagnosed patients. A descriptive cross-sectional study was conducted in the otorhinolaryngology department at the University Teaching hospital and the Central hospital over a period of one year. A total of 250 clinically diagnosed patients of otomycosis of age above one year were included in the study. We evaluated age and sex distribution, predisposing factors and complaints of the clinically diagnosed patients for otomycosis. All samples collected were transported and evaluated by both direct microscopic examination and culture method for bacteria and fungi examination, which were identified by standard procedures. Among 250 samples, 46.22% yielded fungal growth, 21.33% grew bacteria only and 32.44% showed mixed growth of fungi and bacteria. Major fungal isolates were Aspergillus (n=121) including 75 isolates of Aspergillus section Nigri, 20 isolates of Aspergillus section Flavi, 13 isolates of Aspergillus section Fumigati, 8 isolates of Aspergillus section Nudilante and 5 isolates of Aspergillus section Terrei. 48 isolates were identified as Candida species. Major bacterial isolates were Staphylococcus aureus (n=45) followed by Pseudomonas species (n=26), Klebsiella species (n=21), Escherichia coli (n=7) and Proteus species (n=3). This study highlights the highest isolation of Aspergillus section Nigri in cases of clinically diagnosed otomycosis patients at the two reference hospital in Yaoundé, Cameroon with high prevalence seen in patients using antibiotic eardrops as a mean of treatment from pains and itching.