RESUMO
The diagnosis of histoplasmosis due to Histoplasma capsulatum var capsulatum is based on a direct examination identifying encapsulated yeast with narrow-based budding. Galactomannan antigenemia facilitates diagnosis, as well as the monitoring of patients receiving treatment. The case of a HIV-positive patient from Congo-Brazzaville with a disseminated form of African histoplasmosis highlighted the positive galactomannan antigen in this disease due to Histoplasma capsulatum var duboisii. Galactomannan antigenemia remained high with a very slow decrease during antifungal therapy and slow regression of clinical lesions. African histoplasmosis is a rare disease that is difficult to diagnose and rarely described in immunocompromised patients, in whom differential diagnosis can be common. This observation underlines the importance of the galactomannan antigen assay in patients who have travelled to endemic areas. As in the case of Histoplasma capsulatum var capsulatum, the positivity of the Aspergillus galactomannan antigen is very useful in the diagnosis and monitoring of African histoplasmosis.