Prevalence and etiology of onychomycosis in the HIV-infected Mexican population.

Onychomycosis is a fungal infection of the nail caused by dermatophytes, yeasts, and non-dermatophyte molds. Human immunodeficiency virus (HIV)-infected patients are predisposed to this infection. In a cross-sectional study, we estimated the prevalence of onychomycosis and the frequency of fungal agents among HIV-infected patients in Mexico. We enrolled HIV-infected patients diagnosed clinically with onychomycosis from 2008 to 2010. Samples were collected from 300 (84% men) HIV-positive patients by scraping of subungual hyperkeratotic debris and nail plate clipping. All specimens were subjected to culture on Sabouraud agar, Mycosel™ agar, direct microscopy with potassium hydroxide (KOH) and the cultures were incubated at 35 °C for 4 weeks. The prevalence and the 95% binomial confidence intervals were calculated. The mean age (± SD) was 37 ± 9 years. One hundred and twenty-four patients (41%) had clinical signs of onychomycosis and 51 (17%) produced a positive culture. Candida parapsilosis was the most frequently isolated microorganism (13 patients, 20%), followed by Trichophyton rubrum (11 patients, 17%).