Onychomycosis in Africa: Prevalence and Spectrum of Fungal Pathogens

Onychomycosis is commonly reported in Africa, but data on its prevalence and spectrum of incriminated pathogens is fragmented in the literature. Understanding its epidemiology and profiling of the incriminated fungal pathogens would be very useful in managing patients as they are often difficult to treat, especially with the global emergence of antifungal resistance.

We identified a total of 44 well-documented studies in 13 (24.1%) of the 54 African countries amounting to a total of 6773 cases of nail fungal infections: 4609 (68.0%) from North Africa, 1338 (19.6%) from West Africa, 524 (7.7%) from East Africa, 243 (3.6%) from Central Africa, and 59 (0.9%) from Southern Africa, with a pooled prevalence of 19.6% (6773/34604). Identification of fungal pathogens was mainly by conventional methods: microscopy (n = 43, 97.7%), culture (n = 42, 95.5%), and periodic acid-Schiff staining (n = 1, 2.3%). Advanced diagnostics with improved sensitivity were also deployed in some studies: PCR (n = 2, 4.5%), sequencing (n = 2, 4.5%), and matrix-assisted laser desorption/ionization time of flight mass spectrometry (n = 1, 2.3%). The most frequent fungal pathogens identified in North and Central Africa were Trichophyton rubrum (80.4% and 49.3%), followed by Candida albicans (12.2% and 27.4%), respectively, while in the West and East African regions, it was Candida albicans (63% and 47.3%) followed by Trichophyton rubrum (19.1% and 18.9%), respectively. Antifungal susceptibility testing was performed in only five studies and showed varied outcomes with high resistance of dermatophytes to ketoconazole, itraconazole, and fluconazole and non-dermatophyte moulds to caspofungin and 5-flucytosine, respectively.

Onychomycoses are frequent but of less cognizance as data was found from only 13 of the 54 African countries. The emergence of drug-resistant onychomycosis is of concern and informs the need to prioritize research in this area to improve diagnostics and the availability of antifungal susceptibility testing.