I3ugge's case may be considered one of strictly hereditary tuber culosis: A woman, 39 years old, suffering from tuberculosis for two years, died four hours post partum, and her child 26 hours later. Tuber cle bacilli were found in the blood of the child's umbilical vein and in a. section of an hepatic blood vessel. Three guinea-pigs were inoculated with the blood from the umbilical vein, and a bit of lung and of hepatic tissue were inoculated subcutaneously. All three animals died of inocu lation tuberculosis; no tuberculous lesions were found.
If we arc to consider hereditary tuberculosis merely as a rare phenomenon, of little importance in the genesis of the great white plague, then we must give attention to another possibility. Our atten tion must be directed not alone to those few cases in which tubercu losis has been engrafted previous to birth, and which develop the dis ease in the first weeks or months of life, but we must presuppose that the development of tuberculosis may follow after a longer interval.
According to this view, the tubercle bacillus is transmitted far more frequently to the offspring, but lies dormant in the tissues of the child, and for the time being does no harm. Through one circum stance or another, such as an unfavorable mode of life, symbiosis with other disease germs, as, for example, with that of measles, a stimulus and impulse is given to the development of the bacillus, and, in that way, to the outbreak of tuberculosis.
We would thus have to distinguish between the infection of heredi tary origin, and the evolution of the disease, which developed weeks, months, years, even decades later, from the seed sown previous to birth. We would have to attribute to the tubercle bacillus the prop tery of latency, the property of being able to exist permanently in its usual form, or we must say, that it may live in the tissues, capable of development but in a form not yet known to us (larval stage, Baumgarten).
As is well known, Behring, the exponent of the idea of infection during the first few days of extra-uterine life, believes in the longevity of the tubercle bacillus. If this be our standpoint, if we accept the pos sibility of latency, then we can understand that the teaching of the hereditary character of tuberculosis is gaining more and more support.
This view, following the discovery of the tubercle bacillus, was en tirely lost sight of. Baumgarten alone persisted during all these years in his view that the bacillus was frequently transmitted to the offspring, and can witness with pleasure the gradual spread of his ideas (Baum garten, Jahresbericht, 1S9S, vol. xii, p. 570). The entire teaching of the heredity of tuberculosis will always be coupled with the name of Baumgarten. If his view as to the larval stage of the bacillus be correct, then we need not wonder at the negative results of the tuber culin injection in the case of infants who have the germ of tubercu losis in their organism. For the reaction is not the result of a tuber culous infection; the rise in temperature depends rather upon the vital reaction of the bacilli as the result. of the injection of tuberculin.
When we weigh the pros and cons of such a broad interpretation of the heredity of tuberculosis, we must consider in the first place the experience of veterinarians, who show that calves which are im mediately removed from their tuberculous mothers and reared away from all source of contagion, remain healthy.
Human pathology offers analogous observations. My own ex perience would seem to point in the same direction. Immediately after birth, children were separated from their tuberculous mothers and have so far remained free from tuberculosis. On the other hand, I know of three cases where the children of tuberculous mothers were likewise carefully guarded and separated from other tuberculous infec tion, but in spite of this, and although they did not. react to tuber culin in the first weeks of life, they developed tuberculosis with a positive tuberculin reaction later in life.
A classical experiment of this- nature was reported by Epstein at the Meran meeting of German scientists. A child was separated from its tuberculous mother immediately after birth and reared in the found ling asylum with other children. Notwithstanding this, it died of tuberculosis during the first year of its life. On the other hand, the same author reported instances where immediate separation of the mother and the child was followed by absence of tuberculosis in the offspring.