Ecology and epidemiology of dermatophyte infections

Our knowledge of ecology and epidemiology of dermatophytes and the factors influencing their transmission has helped us understand better the natural history of dermatophytoses. It seems that the anthropophilic agents of scalp infection are being eradicated in developing nations. The exception is Trichophyton tonsurans-related tinea capitis in North America. Microsporum canis is a prevalent agent of tinea capitis in many regions of the world, and this could be related to close association of humans with their pets. Trichophyton violaceum is endemic in certain parts of Eastern Europe, Africa, Asia, and South America but not in North America. Trichophyton rubrum is the most common cause worldwide of tinea pedis, nail infection, tinea cruris, and tinea corporis. Although the incidence of tinea capitis is declining in developed nations, tinea pedis and onychomycosis are becoming more common. The increased use of athletic shoes both by men and women and communal bathing could be contributing factors. Five or six species account for most dermatophytoses globally.