Isolation of Trichophyton violaceum and Trichophyton soudanense in Baltimore, Maryland.

Tinea capitis is of public health importance because of its transmissibility. Trichophyton violaceum and Trichophyton soudanense, which are common causes of tinea capitis in parts of Africa and West Asia, have only rarely been reported to cause dermatophytoses in the United States. We identified 24 patients with 25 positive cultures for T. violaceum or T. soudanense that were processed in a single hospital laboratory in Baltimore, Maryland, between 1 January 2000 and 30 June 2006. Most patients for whom clinical information was available had tinea capitis. There was a marked increase in the isolation of these organisms between the period from 2000 to 2002 and the period from 2003 to 2006, possibly associated with changes in immigration to the Baltimore metropolitan area. The changing epidemiology of this transmissible fungal infection not only is of public health interest as an example of the introduction of a "new" pathogen to an area where it traditionally was not endemic but also is of clinical and microbiological importance given reports suggesting an increasing incidence of tinea capitis in some areas and increasing clinical failure rates of current therapies.