The fungus has been linked to exposure to birds, bird feathers, and bats. Histoplasmosis, a type of fungus, exists as a spore in the soil in endemic areas.
Exposure is usually through inhalation of the spore.
Most cases are mild or asymptomatic . The symptoms most commonly occur as a nonspecific respiratory infection similar to a cold or flu . The acute disease may occur in epidemics, with illness lasting for 1 to 6 months, but it is rarely fatal. The acute progressive Histoplasmosis continues to worsen and is often fatal within 6 weeks or less. It involves the liver, spleen, and all the organs of the body.