STUDIES ON THE RISK OF TUBERCULIN POSITIVE CONVERTERS TO DEVELOP THE X RAY MANIFESTATION

抄録

Being the simplest and the most reliable means to detect the tuberculosis infection, the tuberculin reaction constitutes the most important compass to direct the control measures of tuberculosis, because entirely different principles should be followed thereby, if the individuals are infected or not. Tuberculosis infection is widespread in civilized countries, and so the pivot of tuberculosis control measures would be to prevent the infected persons from the onset, or the early treatment of the individuals with so-called primary infection, to prevent them from the development of clinical manifestation.
It is presumed that the intensity of tuberculin reaction is to be largely influenced by such factors as individual reactivities, conditions of tuberculous lesions etc. In spite of numerous studies accomplished and discussions done up to date by many researchers on the relationship between the intensity of tuberculin reaction and the severity of tubercuious lesion, there are many problems yet to be solved. In this connection, it has been proved by us on both animal experiments and BCG inoculation of human subjects, that the appearence of positive conversion of tuberculin reaction is quickened, and the reaction itself is intensified along with the increase in the amounts of tubercle bacilli inoculated. As, thus, the intensities of tuberculin reaction at the time of primary infection, namely, at the time of positive conversion, parallel the amounts of tubercle bacilli infected, it is duly inferable that the intensities of tuberculin reaction on positive conversion may indicate the grades of the risk of subsequent onset of tuberculosis. If it will be possible to prove this inference to be justified, it would be quite an asset for the control of tuberculosis.
The authors conducted, henceforth, the detailed observations as to the groups of personnels under different environments, on the mode of developing tuberculin allergy at the time of primary infection, changes of the tuberculin reaction thereafter, relationship between the tuberculin reaction and the X ray manifestation, time intervals from the time of positive conversion to the onset of tuberculosis, etc. In the present report the findings of these observations will be summarized and discussed.
The personnels utilized in the present investigation were of the following 4 groups:
A: Students in a certain college for males in Tokyo city. The period of observation was from April 1940 to March 1943.
B. Pupils in a certain middle school for males in Tokyo. The period of observation was from September 1941 to March 1944.
C: Male employees aged from 15 to 26 in a certain factory in Kawasaki city. The period of observation was from April 1942 to September 1944.
D. Whole inhabitants of Tomioka village in Saitama prefecture. The period of observation was from August 1939 to March 1943.
Following examinations were carried out as to the individuals of the above mentioned 4 groups.
1. Tuberculin test
Tuberculin test was made with O. T. in a dilution of 1: 2, 000 giving an injection of 0.1 ml intracutaneously into the flexor surface of the forearm. Reading of the reaction was made at the end of 48 hours after injection. Erythema 5-9 mm in diameter was taken as doubtful-positive; 4 mm and below, as negative; 10 mm and over, however, without induration, nor halo, as weakpositive; the same with indu ration, as moderate-positive; and the same with both induration and halo, as strong-positive. The test was repeated on the tuberculin negative and doubtful-positive individuals in A, B and C groups every 3 to 4 months and the same in D group were examined of their tuberculin reaction every year in August.
When an erythema 0-4 mm in the previous examination became 10 mm or over, the change was called as the positive conversion of tuberculin reaction.