Epidemiology and prevalence of onychomycosis in HIV-positive individuals

Background Patients who are human immunodeficiency virus (HIV) positive are predisposed to the development of infections including tinea pedis and ony chomycosis. While smaller studies have been reported, there has been no lar ge study evaluating the prevalence of onychomycosis in HIV-positive individ uals, or comparing the development of onychomycosis in a typical temperate area with that in a typical tropical area. Methods HIV-positive individuals were evaluated at five clinics: four in On tario, Canada and one in Sao Paulo, Brazil. The subjects were asked questio ns to determine the epidemiology of onychomycosis in HIV-positive individua ls. The feet were examined and nail material was obtained for mycologic exa mination to determine the causative organism of onychomycosis. Resutls A total of 500 subjects were examined (415 men and 85 women; age (m ean +/- SE), 39 +/- 0.4 years; 400 Canadian, 100 Brazilian). The racial ori gins of the Canadian patients were: Caucasian, 83.8%; Asian, 4.3%; African- American, 8.1%; Hispanic, 3.3%; American Indian, 0.3%. The Brazilian origin s were: Caucasian, 68.7%; African, 18.1%; mixed race, 13.3%. Abnormal appea ring nails and mycologic evidence of onychomycosis were present in 200 (40. 0%) and 116 (23.2%), respectively, of 500 subjects. The prevalence of onych omycosis in the Canadian and Brazilian samples was 24.0% (96 of 400) and 20 .0% (20 of 100), respectively. The projected prevalence of onychomycosis in HIV-positive individuals in Canada was 19.9% (95% CI: 16.0-23.9%) after ta king into account the age and sex distribution of HIV-positive individuals in the population. When nails appeared clinically abnormal, the prevalence of onychomycosis was 50.5% (Canada, 51.3%; Brazil, 45.5%). For comparison, published data indicate that the prevalence of onychomycosis in immunocompe tent individuals living in Canada is 6.9%. The clinical presentation of ony chomycosis for the whole sample (n = 500) was: distal and lateral subungual onychomycosis (DLSO), 20.0%; white superficial onychomycosis (WSO), 3.6%; proximal subungual onychomycosis (PSO), 1.8% (Canadian and Brazilian sample s: DLSO 21.2% vs. 15.0%, WSO 3.3% vs. 5.0%, and PSO 1.5% vs. 3.0%). The dis tribution of the causative fungal organisms was: dermatophytes : Candida sp ecies : nondermatophyte molds, 73 : 2 : 2 (Canadian and Brazilian samples: dermatophytes 95.5% vs. 90.9%, Candida species 3.0% vs. 0%, and nondermatop hyte molds 1.5% vs. 9.0%). The use of protease inhibitors, reverse transcri ptase inhibitors, or oral antifungal agents did not make a significant diff erence in the prevalence of onychomycosis for both the Canadian and Brazili an groups. Patients with onychomycosis were aware of their abnormal appeari ng nails (chi (2) (1) = 69.7, P < 0.001), embarrassed by the appearance of their nails (chi (2) (1) = 29.7, P < 0.001), and took measures to hide thei r nails from other individuals. A higher proportion of individuals with ony chomycosis experienced discomfort compared with those without the disease ( chi (2) (1) = 9.0, P = 0.003). Also, individuals who experienced pain in th e nail unit were more likely to have onychomycosis (risk odds ratio (ROR), 2.2; 95% CI: 1.0-4.7, P = 0.05). Conclusions The prevalence of onychomycosis in HIV-positive individuals in the sample of 500 patients was 23.2%. In the Canadian (n = 400) and Brazili an (n = 100) samples, the corresponding figures were 24% and 20%, respectiv ely, with the predominant causative organisms being dermatophytes. The proj ected prevalence of onychomycosis in HIV-positive Canadians is 19.9%. Predi sposing factors include a CD4 count of approximately 370, a positive family history of onychomycosis, a history of tinea pedis, and walking barefoot a round pools. Onychomycosis can be symptomatic, a source of embarrassment, a nd a potential cause of morbidity.