Opportunistic fungal infection Histoplasmosis 2019-01-27T18:10:09Z Most patients exhibit pulmonary signs and symptoms, accompanied by radiographic abnormalities, which often are mistaken for community-acquired pneumonia caused by bacterial or viral agents. Most of the infected individuals remain asymptomatic or have very mild illness that does not get diagnosed as histoplasmosis. Significant symptoms develop in less than 1% of patients and most frequently present as pulmonary or disseminated histoplasmosis. Immunocompromised individuals, including patients with AIDS, hematologic malignancies, transplant recipients, and patients receiving prolonged steroids, are at higher risk of developing acute disseminated disease with a rapid and aggressive course. Histoplasmosis is caused by the fungus Histoplasma capsulatum and is consider to be an opportunistic infection in immunosuppressed persons.