[Tinea capitis in Madagascar: a survey in a primary school in Antsirabe].
BACKGROUND: Tinea capitis is a common infection among schoolchildren in developing countries. This condition is still under-reported in Madagascar. In order to assess the prevalence of Tinea capitis in Madagascar, we conducted a study in a primary school in Antsirabe, a town located in the country's high central territories. METHODS: Samples were taken from 210 children in the 4 school classes aged between 6 and 14 years. Only children with scaling lesions or with alopecia were sampled. No microsporic gray-patch ringworm was found in any of the children. Samples were obtained from a total of 83 children. Cotton swabs moistened with distilled sterilized water were rubbed on the children's scalps for 15 seconds and the scales thus collected were then seeded on 2 separate tubes of Sabouraud-Dextrose-Agar media containing chloramphenicol, one with and the other without cycloheximide. The tubes were incubated at a temperature of 27 degrees C for 4 weeks. All the micromycetes were identified (dermatophytes, yeasts and molds). RESULTS: Three species of dermatophytes were isolated: one anthropophilic species, responsible for black-dot ringworm (Trichophyton tonsurans), and 2 geophilic dermatophytes, unusual in human disease (Microsporum boullardii and Trichophyton terrestre). Of the 83 children sampled, 17 had 20 dermatophytes (in 3 children, 2 different species of dermatophytes were associated). We collected 15 Trichophyton tonsurans (2 Trichophyton tonsurans were associated with Microsporum boullardii, and 1 with Trichophyton terrestre), and 2 Microsporum boullardii. The prevalence of carriers of dermatophytes was 8 p. 100 for all children and 20.5% for the sampled children. DISCUSSION: Children in Madagascar, unlike those in Central Africa, do not develop microsporic gray-patch ringworm caused by Microsporum langeronii. However, they may present tinea capitis with small alopecic lesions, or they may frequently have Trichophyton tonsurans and seem to have healthy scalps. In contrast with Central Africa, where T. soudanense is the main cause of black-dot ringworm, and with North Africa, where T. violaceum is most frequently seen, these 2 species are not found in Antsirabe. Studies carried out in coastal regions with a more tropical climate could perhaps show other dermatophytes responsible for tinea capitis. Anthropophilic tinea capitis caused by Trichophyton tonsurans is endemic in the Antsirabe area. The lesions are inconspicuous with diffuse scaling, like those reported in surveys conducted in the USA. Mycological investigation followed up by topical treatment with a fungicide could diminish the spread of this anthropophilic, and thus contagious, dermatophyte. Trichophyton tonsurans has also reappeared regularly in France over the past few years.