Epidemiological characteristics of anthropophilic and zoophilic dermatophytosis: a 40-year retrospective prevalence study

Dermatophytosis is commonly caused by anthropophilic or zoophilic fungi. Although factors related to the disease onset have been identified, it is unclear whether these factors influence disease prevalence differently depending on the fungus's ecological niche. Our study aimed to determine the epidemiological characteristics of dermatophytosis caused by anthropophilic versus zoophilic agents. We conducted a retrospective descriptive study (1976-2015) including confirmed cases of dermatophytosis diagnosed by positive mycological cultures in patients treated at the Institute of Tropical Medicine "Daniel Alcides Carrion"-National University of San Marcos, Lima, Peru. Demographic and microbiological data were collected. We used the Chi-square test to evaluate differences in the prevalence of anthropophilic and zoophilic dermatophytosis across the variables of interest. A total of 4961 cases of dermatophytosis were diagnosed. Anthropophilic dermatophytosis was most prevalent in adults, primarily due to Trichophyton rubrum (92.19%) and T. interdigitale (94.16%) (P < 0.001). In contrast, zoophilic dermatophytosis was most prevalent in children, primarily due to Microsporum canis (64.24%) (P < 0.001). Furthermore, anthropophilic dermatophytosis was most prevalent in tinea unguium due to T. rubrum (61.49%) and T. interdigitale (62.12%), as well as in tinea pedis due to T. interdigitale (37.88%) (P < 0.001). Conversely, zoophilic dermatophytosis was most prevalent in tinea capitis due to M. canis (54.88%), as well as in tinea manum and tinea corporis due to T. mentagrophytes (25.71% and 37.71%, respectively) (P < 0.001). According to its ecology, dermatophytosis was related to the age group affected, the clinical form presentation, and a specific etiology.