Growing Incidence of Non-Dermatophyte Onychomycosis in Tehran, Iran

Abstract

BackgroundNon-dermatophyte onychomycosis (NDO) is caused by a wide range of mold fungi other than dermatophytes, and has been reported at various rates in different countries worldwide. Studies on the incidence of NDO in the community are essential for understanding its epidemiology and control, as well as for the appropriate treatment of these infections.ObjectivesIn this study, the incidence of NDO in Tehran, Iran, was compared to the incidence of onychomycoses due to dermatophytes and yeasts.MethodsFrom 2014 through 2015, samples from a total of 1,069 patients with suspected fungal nail diseases, who were referred to three medical mycology laboratories in Tehran, were collected and subjected to direct examination (all samples) and culture (788 samples). Differentiation of the causative agents of onychomycosis was based on microscopic observation of characteristic fungal elements in the nail samples and growth of a significant number of identical colonies on the culture plate.ResultsBased on only direct microscopy, onychomycosis was diagnosed in 424 (39.6%) cases, among which 35.8% were caused by dermatophytes, 32.7% by yeasts, and 29.3% by non-dermatophyte molds (NDMs), while 2.2% were mixed infections. Direct exam was significantly more sensitive than culture for the diagnosis. The most commonly isolated NDMs were Aspergillus spp. (69.3%, n = 52), followed by Fusarium spp. (n = 7). The other isolated species were Paecilomyces spp., Scopulariopsis spp., Acremonium spp., Cladosporium spp., and Chrysosporium spp., with only one case of each.ConclusionsAn increasing frequency of NDO compared to onychomycosis due to other causative agents has been noticeable over the past few years in Iran. This epidemiological data may be useful in the development of preventive and educational strategies.

Mycological Aspects of Onychomycosis in Khuzestan Province, Iran, a New Scenario as Shift from Dermatophytes towards Yeasts

“…Review of the literature and the data from this study point out that contrary to the popular belief emphasizing on the dermatophytes as the leading causes of onychomycosis worldwide, it is at least from one decade ago that yeasts (alone or in combination with NDMs) are the main agents of onychomycosis in most areas of Iran [ 11 , 12 - 14 , 30 ], and even other parts of the world [ 5 , 21 , 23 ].…”

An Assessment of In Vitro Antifungal Activities of Efinaconazole and Itraconazole against Common Non-Dermatophyte Fungi Causing Onychomycosis

“…A 2015 study showed non-dermatophyte moulds emerging as a leading cause of onychomycosis in south-east Rajasthan in India [ 4 ]. In 2016, a growing incidence of non-dermatophyte onychomycosis was reported from Tehran, Iran with Aspergillus as the most common cause, followed by Fusarium [ 5 ]. NDF have also been seen to colonize damaged nail plates [ 6 ].…”

Clinico-mycological study of onychomycosis

“…Among NDMs the isolation rates of various species vary Fusarium spp (31%) is in accordance to recent case reports and epidemiological studies. 5,[26][27][28][29][30] Although study is not a comprehensive epidemiological survey this study demonstrated that 29.3% of onychomycosis cases are due to NDMs, which is 3 times more than the isolation found in the last study conducted in Bangalore, India. 12 The fact that non-dermatophyte moulds is the most common pathogen implicated for onychomycosis in this population, poses a challenge as its response to oral antifungal is unpredictable.…”

“…Similar pattern of isolation was noted in recent studies. 5,6,17,18 The presence of superficial fungal infection was seen among seven patients, majority of whom had tinea pedis. T. rubrum was most commonly isolated in this group, which is in accordance with previous studies.…”

“…2020 Jan;6(1): [89][90][91][92][93][94] International Journal of Research in Dermatology | January-February 2020 | Vol 6 | Issue 1 Page 90 countries of Asia (40.5% to 68%) including India (13.6%-53.33%). [3][4][5][6][7][8][9] Thus NDMs, previously considered as mere contaminants have emerged as potential pathogens in the tropical regions, in comparison to the traditional isolate of dermatophytes. 10 In the current study, the demographic data, clinical features and fungal spectrum of patients presenting with onychomycosis was reported.…”