It is an uncommon disease. Anyone can get histoplasmosis. It is recognized more often in immunocompromised individuals, such as AIDS patients. The disease is acquired by inhaling the spore stage of the fungus. Outbreaks may occur in groups with common exposures to bird or bat droppings or recently disturbed, contaminated soil found in chicken coops, caves, etc.
Symptoms vary from mild to severe, ranging from a flu-like illness to serious lung infections.
In immunocompromised patients, the disease may spread to the bone marrow, lungs, liver, and lymph nodes. However, most people do not experience any symptoms. Infection usually results in increased protection against repeat infection, although the immunity is not complete. Histoplasmosis is diagnosed by isolating the fungus from body fluids or tissues, visualizing the fungus under the microscope, or by an antibody test. Specific treatments, such as amphotericin B, are available for patients with severe illness.