Definition of Histoplasmosis

Histoplasmosis is a disease caused by the fungus Histoplasma capsulatum.  The fungus lives in the environment, usually in association with large amounts of bird or bat droppings.  Lung infection can occur after a person inhales airborne, microscopic, fungal spores from the environment; however, many people who inhale the spores do not get sick. The symptoms of histoplasmosis are similar to pneumonia, and the infection can sometimes become serious if it is not treated, especially if the infection spreads from the lungs to other organs.