Histoplasmosis risk factors

Risk factors for histoplasmosis infection include living in or traveling to the Central or Eastern United States. Patients with immunosupression, hematological malignancies, immunosuppressive therapy and infants are at a higher risk of developing disseminated histoplasmosis infection.

Risk factors for pulmonary histoplasmosis include:

• Living in or traveling to the Central or Eastern United States.
• Activities such as spelunking, mining, construction, excavation, demolition, roofing, chimney cleaning, farming, gardening, and installing heating and air-conditioning systems.
• Activities that expose people to areas where bats live and birds roost also increase risk. Exposure to soil or particles contaminated with droppings of chickens, bats, or blackbirds is the main mode of transmission.^[1]

Risk factors for severe acute disease or disseminated disease include:

• Infants
• Immunocompromised states
• AIDS Patients with CD4 counts of less than 150 cells/mm³ are at highest risk^[2]
• Hematologic malignancies
• Solid organ transplant^[3]
• Hematopoietic stem cell transplant
• Use of immunosuppressive agents such as corticosteroids and tumor necrosis factor antagonists
• Congenital T-cell deficiencies
• Gamma interferon receptor deficiency
• Hyperimmunoglobulin M syndrome is a risk factor for refractory and recurrent disseminated histoplasmosis