Trichophyton tonsurans infection among judo practitioners from schools in Saga Prefecture, Japan: A group screening report

Abstract

A group screening of a total of 643 Judo club members (198 high school, 258 secondary school, and 187 pre- and elementary school students) was carried out to identify infection with Tnchophyton tonsurans (T. tonsurans). Among the 198 high school students, 50 (46 males, 4 females) developed positive cultures: 9 (4.5%) displayed only tinea capitis, 22 tinea corporis (15 individual, 3 tinea capitis comorbid, and 4 HB-positive cases), 1 tinea manum, and 18 (9%) were aymptomatic carriers. The fact that out of 22 cases of tinea corporis, 7 (31%) carried the fungus in their hair proves the necessity of a closer examination of the hair, including the hairbrush (HB) method, when diagnosing tinea corporis. Three to 4 months after the first screening, tinea capitis patients and fungus carriers were requested to fill out a questionnaire concerning the treatment they had received and were the subjects of a second HB screening. We found that for tinea capitis a ≥ 1.5 month oral treatment with antifungals was successful in eliminating the fungus. For carriers with ≤2 fungus colonies previously found during the first screening, simply washing the hair with a shampoo containing antifungal agents led to the elimination of the fungus, without necessarily requiring oral treatment. Fourteen (5.6%) secondary school students out of 258 were infected with T. tonsurans (11 HB-positive, 2 tinea capitis, 3 tinea corporis cases, and 3 carriers; comorbid cases included). Also, 2 (1%) out of 187 pre-secondary students had the fungus (2 tinea corporis cases). These findings confirm the transmission of the fungus in the lower grades. Considering how easy it is to become a carrier of T. tonsurans and that, because tinea corporis often displays atypical exanthema, the infection can be misdiagnosed as eczema, it is important to actively perform KOH examination, culture and HB screening.