ISTOPLASMOSIS was first described in 1906 and until about 1940 it was considered to be an acute, progressive, almost invariably fatal disease. It is now recognized that in addition to the progressive disseminated type there is a much commoner type that is benign, self-limited, and often asymptomatic.1 According to Tegeris and Smith2 the case fatality rate in epidemics is about 1.2%. The distribution seems to be world-wide but the disease is more prevalent in rural than in urban areas and in some rural regions than in others.3 The causative fungus, Histoplasma capsulatum, is found in the feces of birds (especially domestic fowl), bats, dogs, and various other mammals, hence it is commonly found in the soil.
Primary infection with the development of a single tuberculoid nodule in the lung is almost always of the benign type but, if there is an overwhelming exposure to contaminated dust, multiple
HISTOPLASMOSIS. JAMA. 1958;168(17):2272. doi:10.1001/jama.1958.03000170064014