Onychomycosis in a Community of Garbage Collectors in Northeast Brazil

摘要

Onychomycosis is a fungal infection of the nails that can cause an important adverse impact on the quality of the affected individual's life. This study aimed to evaluate the prevalence and to identify the predominant pathogens of onychomycosis among a population of Garbage Collectors. A clinical sample of the nail abnormal was submitted to direct mycological exam (NaOH) and culture in Sabouraud's agar and Mycosel medium. Of the 80 garbage collectors examined, 45 were male and 35 female. Among examined individuals, 24 (30%) presented nails with abnormal aspects. Direct exam was positive in 20 samples. Culture was positive in 23 samples. The etiologic prevalence of onychomycosis was: 12 (50%) Trichophyton rubrum, 08 (33.3%) Candida spp., 03 (12.5%) Trichosporon beigelii. This study demonstrated the high prevalence of onychomycosis among garbage collectors. The mains agents causing onychomycosis in this population was T. rubrum, Candida spp and T. beigelii. Introduction Onychomycosis, fungal infection of the nail, is a common medical problem of adults that can cause an important adverse impact on the quality of the affected individual's life, leading to reduced self-esteem and possibly affecting work potential.1,2 It is an infection usually caused by dermatophytes, yeast, and non-dermatophytic moulds.3 Recently, it has been reported that about 20% of persons between 40 and 60 years of age have onychomycosis, and it represents around 30% of all superficial mycotic infection and 50% of nail disorders.1,3,4 Frequent exposure to fungus, damage by trauma or disease, irrational use of antibiotics, HIV infection and immunosuppressive drug therapy are some predisposing factors for onychomycosis.1 The importance of the study of onychomycosis lies in the increase of its prevalence. In the United States of America, it is estimated at between 2% and 13% present onychomycosis, again the more elderly individuals presenting this infection in a percentile that varies from 15% to 20% and can reach as much as 50%.2 This study aimed to evaluate the prevalence and to identify the predominant pathogens of onychomycosis among a population of Garbage Collectors. Materials and Methods Participants (Garbage Collectors)Over a period of three months (March 2008 - May 2008), residents in a community of garbage collectors, living around the landfill of Itabuna′s city, northeast Brazil, were briefed about the aims of the study and invited to participate. All participants signed the informed consent form. The research protocol was approved by the Ethical Committee of State University of Santa Cruz. The clinical specimens collected were sent to the Microbiology Laboratory of State University of Santa Cruz for mycological analysis.Specimen Collection and ProcessingThe participants were examined and the nails of hands and feet were classified as normal or abnormal. The specimens, obtained from clinically abnormal nails, were cleaned with 70% alcohol and a nail dust samples were taken from the nail bed after subungual scraping from the most proximal part of the lesion. In the case of onycholysis, the nail was cut back and material was scraped off the underside of the nail and from the nail bed. Classification of the onychomycosis was based on the four specific clinical types of alteration presented, according to the method of Roberts and colleagues (1990).5 Distal and lateral subungual onychomycosis. White superficial onychomycosis Proximal subungual infection Total dystrophic onychomycosis The samples of each patient were placed in separate sterile Petri dish and transported to Microbiology Laboratory. Scales scraped from the nails were analyzed for fungal elements, such as hyphae or blastoconidia, by direct microscopy examination, in NaOH (30%). For fungal cultures, all samples were inoculated on each of two isolation media (i) Sabouraud glucose agar (SGA; Difco Laboratories, Detroit, MI) and (ii) Mycosel agar (Sanofi, France). The culture tubes were incubated