The epidemic of the multiresistant dermatophyte Trichophyton indotineae has reached China

Abstract

Due to its high degree of natural resistance to terbinafine in vitro and its tendency to spread globally from the Indian subcontinent, the emerging dermatophyte Trichophyton indotineae has become a major concern in dermatology. Herein, we present the first report of T. indotineae from mainland China. The transmission of the fungus to Guizhou Province in central China and eventual host susceptibilities were investigated. We studied 31 strains of the T. mentagrophytes complex from outpatient clinics of our hospital collected during the past 5 years. The set comprised four ITS genotypes, two of which were T. mentagrophytes genotype VIII, now known as Trichophyton indotineae; the earliest isolation in the Guiyang area appeared to date back to 2018. The isolate was derived from an Indian patient, while local Chinese patients had no dermatophytosis caused by this genotype. Reports from around the world indicated that almost all of the globally reported T. indotineae cases originated from the Indian subcontinent and surrounding countries without transmission among native populations, suggesting deviating local conditions or racial differences in immunity against this fungus.

Dermatophyte Infections Worldwide: Increase in Incidence and Associated Antifungal Resistance

“…This resistance was initially noted in India but has also now been reported in parts of Europe [76]. Additionally, similar observations from other countries such as Iran, Japan, and China have been also reported [14,77,78], as well as recently in the United States [79,80].…”

Treatment of onychomycosis in an era of antifungal resistance: Role for antifungal stewardship and topical antifungal agents

“…Although reports of resistance to these drugs were relatively rare in the early 2000s, reports from around the globe of resistance among Trichophyton species have since become increasingly common. Reported rates of Trichophyton resistance to these drugs in clinical isolates from patients with fungal infections including onychomycosis, published mostly between 2017 and 2023, are presented in Figure 2, highlighting both the global spread and regional variability in rates of antifungal resistance 7,9,19,21–41 …”

Emerging Antifungal Resistance in Fungal Pathogens

“…Around 2017–2018, a drug-resistant variant of T. indotineae emerged in India, setting off a global spread from the Indian subcontinent [ 55 , 56 ]. Reported cases are seen in several countries, including India, Bahrain, United Arab Emirates, Oman, Iran, Germany, France, Italy, Belgium, Switzerland, Greece, Denmark, Finland, China, Australia, Canada, Japan, Vietnam and the United States of America [ 55 , 58 – 69 ].…”