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: