Trends in the epidemiology of dermatophytes and related infections in Iran
The changes in the epidemiology of dermatophyte fungi and related infections (Dermatophytosis or tinea) in Iran are presented here. A comprehensive literature search was carried out. We found that mycological and clinical features of dermatophyte infections in Iran have significantly been altered during the time. Tinea capitis has remained as the main dermatophytosis in preschool and school-age children all over the country though its occurrence has notably decreased. In higher age groups, tinea pedis followed by tinea corporis and tinea cruris were the more abundant infections and currently increase in their occurrence is sensible. Some infections were correlated with some age groups and special species. The anthropophilic species Trichophyton schoenleinii and T. violaceum were the main species causing infection in the past whereas currently most prevalent causative agents are Epidermophyton floccosum, T. rubrum, T. tonsurans and T. mentagrophytes / T. interdigitale species group (TMTISG). The incidence of dermatophytoses, caused by zoophilic species Microsporum canis and T. verrucosum has decreased. Nannizzia fulva is the most abundant species found in the soil but N. gypsea is the dominant geophilic species isolated from clinical specimens. In Iran, currently, there is an emergence of infections with less-frequent and non-indigenous species e.g. T. benhamiae, T. simii, M. ferrugineum and also the long-forgotten species T. eriotrephon, all of which were detected by DNA sequencing. Some recently isolated clinical Trichophyton strains, phylogenetically close to T. benhamiae, T. simii and T. quinckeanum potentially represent new species.