Human and Zoonotic Dermatophytoses: Epidemiological Aspects

Abstract

IntroductionDermatophytes are a group of molds characterized by the ability to produce keratinases, thereby carving out for themselves specific ecological niches. Their traditional division into three genera, Trichophyton, Microsporum, and Epidermophyton has been expanded to nine and the species in each genus were modified. Dermatophytes are among the most prevalent causes of human and animal mycoses. Their epidemiology is influenced by various factors. These factors may be evolutive such as the predilected environment of the fungus, namely, humans (anthropophilic), animals (zoophilic), or environment (geophilic), is evolutionary and thus may require centuries to develop. Many other factors, however, result from a variety of causes, affecting the epidemiology of dermatophytoses within a shorter time frame.ObjectiveThis review aims at summarizing the factors that have modified the epidemiology of dermatophytoses during the last decades.ResultsGeographic and climatic conditions, demography such as age and gender, migration, socio-economic conditions, lifestyle, and the environment have had an impact on changes in the epidemiology of dermatophytoses, as have changes in the pattern of human interaction with animals, including pets, farm, and wild animals. A typical example of such changes is the increased prevalence of Trichophyton tonsurans, which spread from Latin America to the United States and subsequently becoming a frequent etiological agent of tinea capitis in Africa, Middle East, and other areas.ConclusionThe comprehension of the epidemiology of dermatophytoses has a major bearing on their prevention and treatment. Since it is undergoing continuous changes, periodic assessments of the most recent developments of this topic are required. This article aims at providing such an overview.

Transmission of Onychomycosis and Dermatophytosis between Household Members: A Scoping Review

“…In one study of 101 guinea pigs with dermatophytosis, 98 (97%) were positive for T. mentagrophytes and 24% of households had family members with clinical signs of dermatophytosis, with greater involvement in children than adults [61]. There have also been multiple reported outbreaks of T. benhamiae and T. rubrum in humans attributed to small rodents, including guinea pigs and rabbits, through genotyping techniques [60,62,63]. In many cases, pets were brought into the household just weeks prior to development of clinical symptoms in adults, which reinforces the need to properly examine new pets entering the household to prevent introduction of fungal pathogens [61].…”

Airborne dermatophyte propagules concentration in cowsheds as an underestimated reservoir of potential zoonoses

“…These diseases are highly transmissible and clinically varied from mild to severe, depending on the host's immune status, strain virulence and other environmental factors (Gnat et al, 2020; Gnatet al 2019; Martinez‐Rossi et al, 2021). Dermatophyte infections in the principal pets and livestock animals are a major public and veterinary health problem (Segal & Elad, 2021). The aetiology, epidemiology and symptomatology of these mycoses are quite heterogeneous and complex (Gnat et al, 2019; Łagowski et al, 2019).…”

“…The aetiology, epidemiology and symptomatology of these mycoses are quite heterogeneous and complex (Gnat et al, 2019; Łagowski et al, 2019). Moreover, animal dermatophytoses are caused by zoophilic or geophilic species of dermatophytes, with rare exceptions, especially Trichophyton rubrum complex, assumed to be the result of anthropo‐zoonotic transmission (10.1023/A:1006944605066, 1998; Gnat et al, 2018; Segal & Elad, 2021). Zoophilic dermatophytes species include mostly Trichophyton mentagrophytes , T. verrucosum, Trichophyton benhamiae, Trichophyton erinacei, Trichophyton quinckeanum, Microsporum canis, Nannizzia nana and Lophophyton gallinae (de Hoog et al, 2017).…”

Antifungal activity of alexidine dihydrochloride in a novel diabetic mouse model of dermatophytosis

“…Furthermore, there has been a perceptible epidemiological shift in species from the previously predominant anthropophilic T. rubrum to T. mentagrophytes complex, a zoophilic fungus (Poojary et al, 2019;Adebiyi and Gugnani, 2020). Such a changing trend in etiology has paralleled the rate of increase in households harboring domestic pets, an important source of transmission (Segal and Elad, 2021). Making matters worse is the emergence of drug recalcitrance in these fungi, resulting in inevitable recurrences despite prolonged antifungal treatment (Martinez-Rossi et al, 2018;Khurana et al, 2019).…”