Our present knowledge of the first infection with tuberculosis is the result of a careful correlation of postmortem findings, much animal experimentation and repeated roentgen examinations. Briefly, it may be said that the desire to understand fully this perplexing problem has persuaded all physicians interested in tuberculosis to combine their efforts to the extent that we are now able to say that we have a fairly accurate understanding of the entire primary complex as it occurs in both the child and the adult.
It is a little less than twenty years ago since our knowledge of the tuberculous infection, as it occurred in the child, was so meager and uncertain that the clinician looked on the roentgen examination as only one link in a chain of evidence necessary to decide whether or not the child had tuberculosis. We knew then, as we do now, that the first infection with tuberculosis
BIRKELO CC. ROENTGEN DIAGNOSIS OF THE PRIMARY TUBERCULOUS INFECTION. JAMA. 1942;118(5):350-353. doi:10.1001/jama.1942.02830050012003