The epidemiology and etiology of onychomycosis in 2 laboratory centers affiliated to Tehran university of medical sciences during 2019-2020

Abstract

Background and Objectives: Onychomycosis is caused by dermatophyte species, non- dermatophyte moulds (NDMs), and accounts for roughly 50% of all nail diseases. As the prevalence of onychomycosis is increasing, new epidemiologic documents may help with treatment and prevention. The present investigation aims to determine the epidemiological profile of onychomycosis in 2 mycology laboratories.
 Materials and Methods: A cross-sectional study conducted during eight months (2019-2020) on 169 patients with positive nail mycology tests referred to two mycological laboratory centers affiliated with Tehran University of Medical Science. The nail clippings were examined by direct smear and culture. Also, molecular assays were performed if needed.
 Results: 10% of nail lesions referred to Razi Hospital (RH), and 30% of nail lesions referred to TUMS mycology laboratory were positive. Middle age (40-60) suffer more from onychomycosis. Aspergillus flavus, Trichophyton mentagrophytes, and Candida albicans were the most common etiologic agents in each of the three main classes of fungi causing onychomycosis. Females were more infected. NDMs were the predominant etiologic agents, and toenails were the most common site of onychomycosis.
 Conclusion: The pattern of etiologic agents and clinical signs of onychomycosis differs according to geographical region and age, so repeated epidemiological surveys of onychomycosis seem to be fundamental.

A comprehensive review of nondermatophyte mould onychomycosis: Epidemiology, diagnosis and management

“…A summary of NDM prevalence reported across studies stratified by the geographical location, as well as by the sampling method used (all studies vs. repeated sampling), is shown in Table 1 4–77 . Although the adoption of repeated sampling can increase the diagnostic confidence in a case of NDM onychomycosis, ruling out isolation of the facultatively pathogenic agent as a random contaminant, we did not find significant differences in the predominant NDM strain detected from studies with repeated and unrepeated sampling procedures except in North America 7–13 …”

Novel and Investigational Treatments for Onychomycosis

“…NDMs attribute to 8–11% of infections in Asian countries [ 3 ]. According to a recent Iranian report [ 4 ], samples collected by two laboratories affiliated with Tehran University exhibited 33.7%, 21.8%, and 44.4% rates for yeast, dermatophyte, and NDM onychomycoses, respectively. This is a remarkably different epidemiologic pattern compared to that demonstrated in the Western world.…”