What organism is associated with exposure to bat or bird droppings?

Histoplasma capsulatum is the correct answer because it is a fungus that thrives in environments contaminated with bird or bat droppings, particularly in areas with a high concentration of these organic materials. The spores of Histoplasma can be aerosolized when the droppings are disturbed, allowing for inhalation of the organism. Once inhaled, it can cause a pulmonary infection, which may range from mild illness to severe respiratory disease.

In contrast, Coxiella burnetii is associated with exposure to cattle, sheep, and goats, leading to Q fever, and is not linked to bat or bird droppings. Chlamydophila psittaci is primarily related to exposure to infected birds, particularly parrots, and is the cause of psittacosis, not specifically tied to droppings from bats. Hantavirus is transmitted primarily through rodent droppings and urine, particularly from deer mice, and does not involve bats or birds. Hence, Histoplasma capsulatum is specifically associated with bat and bird droppings, making it the most appropriate organism in this context.