Histoplasmosis, tuberculosis and coccidioidomycosis.

Abstract

The present concepts of histoplasmosis have resulted, in large part, from a more critical examination of disease processes that were formerly considered to be almost exclusively of tuberculous origin. Prior to 1945 the infrequent reports of cases of histoplasmosis suggested little association with tuberculosis aside from the pathological impression that each appeared, usually, as a chronic granulomatous infection. By 1945, however, evidence had accumulated for the existence of pulmonary calcifications demonstrated roentgenologically in a large number of persons, insensitive to tuberculin, who lived in middle western and contiguous states.1Furthermore, to add emphasis to the problem of such calcifications in this area, an analysis of draft board chest roentgenograms, reported in 1943 showed that the Middle West was the region of highest prevalence of this condition in the United States.2Such a geographic distribution did not correspond at all well with tuberculosis mortality.3Following the observations of