Onychomycosis in Gabon: Clinical and mycological data

Objective. - Onychomycosis is the most frequent nail disease, it stands for half of all nail abnormalities. The frequency of onychomycosis in the whole population ranges between 2 and 26.9% according to published data. In temperate countries, yeasts, dermatophytes and moulds are the main agents. Few studies on onychomycosis have been led in Sub-Saharan Africa. This study aimed at determining clinical and mycological data of onychomycosis in Gabon. Patients and methods. - A retrospective, descriptive study on files of patients who were medically consulted for onychomycosis, from January 1986 to December 2009 (24 years), was achieved within the department of parasitology-mycology of the faculty of medicine and health sciences in Owendo. Selected files ought to include clinical description of lesions, positive culture with positive or negative direct microscopy examination of the nails samples, or negative culture with positive direct microscopy examination of the nails samples. Files without sex or age, clinical or mycological data, were rejected. Results. - The population of our study included 1771 patients with an average of 36.9, 1107 of which (62.5%) were women. Onychomycosis was located on fingers for 904 patients (51%), on toes for 1130 (68.8%) and on both, fingers and toes, for 263 (23.3%). Infection was bilateral on fingernails in 364 cases (40.3%) and on toenails in 754 cases (66.7%). The average number of infected nails was respectively 5.3 +/- 2.9 and 5.8 +/- 3.0. Distal and lateral subungual onychomycosis, most common clinical form, was more frequently observed on toes (52.5%) than fingers (35.9%). Interdigital tinea pedis were coexisting with toenail infection in 68.4%, and sole tinea pedis in 58.8%. Tinea corporis and tinea capitis were found respectively in 11.1% and 10% of patients with fingernails infection. Microscopic examination and culture were positive for 823 samples (91%) of fingernails and 965 (85.4%) of toenails. Negative microscopic examination and positive culture were observed in 59 cases (6.6%) on fingernails and 120 cases (10.6%) on toenails, such as positive microscopic examination and negative culture in 22 cases (2.4%) on fingernails and 45 cases (4%) on toenails. Four groups of fungi were isolated in pure and mixed culture. Yeasts represented 77.5% on fingernails, 48.4% on toenails; dermatophytes 12.5% on fingernails, 20.8% on toenails; pseudodermatophytes 5.6% on fingernails, 20.5% on toenails; and moulds 4.4% on fingernails, 10.3% on toenails. Candida albicans represented 48.9% of isolated yeasts on fingernails lesions and 23.4% on toenails. About dermatophytic onychomycosis, T. soudanense was isolated in 43.3% on fingers and T. interdigitale in 54.3% on toes. Conclusion. - Patients examined for onychomycosis in Gabon had an average age of less than 40 years old, and were mainly women. The infection was dominant on toenails and was very often bilateral. Distal and lateral subungual onychomycosis was the most common clinical aspect. Yeasts were the main agents isolated on fingernails, whereas on toenails dermatophytes and pseudodermatophytes were observed at the same proportion. (C) 2011 Elsevier Masson SAS. All rights reserved.