“Initial Foci”, a Special Group of Minimal Tuberculosis. Prognosis and Treatment

Abstract

In the Diagnostic Standards of the National Tuberculosis Association, U. S. A., “minimal tuberculosis” is described in the following manner:1 “Slight lesions without demonstrable excavation confined to a small part of one or both lungs. The total extent of the lesions, regardless of distribution, shall not exceed the equivalent of the volume of lung tissue which lies above the second chondrosternal junction and the spine of the fourth or body of the fifth thoracic vertebra on one side.” Cases of this type have become increasingly common since the Introduction of mass miniature radiography. On closer examination of these cases, it is, however, obvious that the changes In “minimal tuberculosis” vary quite considerably. They may be of exudative, of productive and fibrotic, of exudative-productive or of fibro-calcific type. It may, therefore, be considered impossible to determine a common prognosis and a uniform therapy for all cases of “minimal tuberculosis.” In addition, age, sex, race, general and individual resistance, etc., strongly influence the development of tuberculosis and the therapeutic possibilities. In cases of “minimal tuberculosis” the nature of the changes must, therefore, be carefully stated, cases with identical changes collected and the prognosis and the therapy determined In each separate group. In my opinion, it is only In this way, that greater certainty can be achieved in this question. Such a well delimited group of “minimal tuberculosis,” was named by Malmros and myself in 1938 “initial foci.” Radiologically these show great uniformity and, on the whole, this probably also holds true as regards the pathological-anatomical changes, which cause the deviations from the normal In the x-ray photographs. “Initial foci” constitute the first changes in post-primary pulmonary tuberculosis (Ranke’s stages II and III), and they form the starting point for ordinary pulmonary tuberculosis. Thus, we are dealing here with Incipient tuberculosis In Its earliest form. In order to be able to collect material of this type one of the two following methods may be employed. One consists of taking x-ray photographs at very short intervals of individuals with definite primary tuberculosis until, in some cases, changes of post-primary type develop. The other method, employed by Malmros and myself in an eight-year investigation2’3 consists of following the development of tuberculosis the whole course from the primary Infection until the development of post-primary pulmonary tuberculosis. We put under control for tuberculosis 3,336 indivIduals, of whom 2,902 were students at the University of Lund and 434 probationary nurses from the same town. X-ray photographs were taken