Histoplasma duboisii

Histoplasma duboisii is a species of fungus that is pathogenic to humans. It is a member of the genus Histoplasma, which also includes the closely related species Histoplasma capsulatum. H. duboisii is primarily found in Africa and is the causative agent of African histoplasmosis, a disease that can affect both the skin and internal organs.

Taxonomy

Histoplasma duboisii was first described in 1952 by the Dutch physician A. J. P. Dubois, after whom the species is named. It is classified within the phylum Ascomycota, the largest phylum of fungi, which also includes many other medically important fungi such as Candida albicans and Aspergillus fumigatus.

Morphology

Like other species in the genus Histoplasma, H. duboisii is a dimorphic fungus, meaning it can exist in two different forms depending on the environmental conditions. In the environment, it grows as a mold with filamentous hyphae. However, when it infects a host organism, it transforms into a yeast form.

Pathogenesis and Clinical Features

Histoplasma duboisii causes a disease known as African histoplasmosis. This disease is similar to the more common histoplasmosis caused by H. capsulatum, but it tends to cause more severe skin and bone lesions. The fungus is inhaled as spores, which can then disseminate throughout the body. Symptoms can include fever, weight loss, and skin lesions, and the disease can be fatal if not treated.

Diagnosis and Treatment

Diagnosis of African histoplasmosis is typically made by identifying H. duboisii in tissue samples or by serological tests. Treatment usually involves antifungal medications, such as amphotericin B or itraconazole.

Epidemiology

Histoplasma duboisii is primarily found in Africa, particularly in West and Central Africa. However, cases have also been reported in other parts of the world, including Europe and the Americas, usually in individuals who have traveled to endemic areas.

See Also

• Histoplasma capsulatum
• Histoplasmosis
• African histoplasmosis