Tinea pedis outbreak in swimming pools in Japan.

This study was conducted to show a higher prevalence of interdigital tinea pedis in athletes by comparing athletes and non-athletes, and to examine swimming pools as a route of infection. The subjects were 282 athletes, 137 non-athletes, and 140 students enrolled in a swimming class at the University of Tsukuba. This study included the taking of cotton-swab samples from the interdigital skin surfaces of both feet and cultures, microscopical examinations of scales collected from subjects with lesions, and questionnaires. There was a significant difference between athletes and non-athletes in the prevalence of the relevant pathogens, and a higher risk of infection was shown in athletes. The study also found that 63.6% of the swimming class students were carriers, and that 85.0% of their dermatophytes were Trichophyton mentagrophytes. In addition, dermatophytes were also isolated from the floors of the swimming pool and the public baths. The results of these controlled studies suggested that there was a significant risk of dermatophytosis in both athletes and non-athletes using the swimming pool.