174 



SCIENCE 



[N. S. Vol. XXXIX. No. 996- 



For some time I have been collecting data 

 which enable us to extend these generaliza- 

 tions still further. It has been found that 

 tuberculosis follows typhoid fever far more 

 frequently than physicians have suspected, 

 and moreover the tuberculosis mortality 

 curve of a nation is almost always parallel to 

 that of typhoid fever. Cities do not show 

 such a close agreement as the country as a 

 whole, because consumptives quite commonly 

 leave the city to die elsewhere. As far as the 

 very defective statistics permit a conclusion, 

 it is to the effect that consumptives have had 

 much more typhoid fever than the rest of the 

 population. We have long known of the seri- 

 ous after effects of typhoid fever, but only re- 

 cently have a few physicians been calling at- 

 tention to the far-reaching nature of these 

 sequelse. Tuberculosis is only one of these re- 

 sults. That is, by reducing typhoid fever in 

 any way whatever we save far more from death 

 by numerous other conditions due to the less- 

 ened resistance caused by the typhoid infec- 

 tion. The purification of a water supply is 

 then only one of the numerous ways of reduc- 

 ing tuberculosis. 



The explanation of the phenomenon is evi- 

 dent. By personal inquiries of physicians in 

 the United States, Germany, Switzerland, 

 France and Great Britain, I find that the fol- 

 lowing facts seem proved to the minds of 

 those who by special study are competent to 

 form an opinion. Babies are born free of 

 tuberculosis, but begin to acquire it as soon 

 as they can crawl around, pick up the bacilli 

 with dust and dirt, and immediately convey 

 them to the mouth after the manner of all 

 babies. These germs are weakened or attenu- 

 ated by sunlight, drying, etc., and are not able 

 to spread actively, though they establish them- 

 selves. Those which are taken in by the 

 phagocytes have the same effect as vaccination 

 and cause the production of antibodies which 

 make us all more or less immune to infection 

 by virulent bacilli. K a baby is infected by 

 fresh virulent bacilli from a nurse, before 

 its immunity is produced, it dies of rapid dis- 

 seminated tuberculosis, but an adult is not 

 harmed by the virulent bacilli he takes in. 



Indeed, there is no incontrovertible evidence 

 that any adult ever acquires tuberculosis. If 

 one develops active tuberculosis, it is not a 

 new infection, but an activation of latent 

 lesions he has been carrying since childhood. 

 Something has happened to him which has 

 caused a temporary lessening of his antibodies 

 and allowed the latent tuberculosis to spread — • 

 and nothing is more potent in doing this than 

 the infections like measles, whooping cough 

 and typhoid fever. Without these activating 

 causes a man may lose immunity very slowly 

 by improper food, mental and physical ex- 

 haustion, living in badly ventilated rooms, 

 lack of outdoor exercise and a thousand other 

 ways of lowering general health, but if one in 

 such a condition does acquire another infec- 

 tion like pneumonia, typhoid fever or in- 

 fluenza, his chances of becoming actively 

 tubercular later are very large. Post-mortems 

 of children almost always reveal tubercle, no 

 matter what the disease was which caused 

 death. Post-mortems of adults always show 

 healed lesions, proving that at some time in 

 our lives each of us lost resistance sufficiently 

 to allow the lesions to become active, though 

 we were later cured by a reestablishment of 

 the immunity. One eighth or one tenth of us 

 are unable to reestablish it and perish from 

 tuberculosis. The facts are bound to modify 

 the anti-tuberculosis crusade most profoundly. 



Savages, living an outdoor isolated life, 

 have no chance to encounter tubercle bacilli 

 and consequently do not become immune. 

 When they do come in contact with a case- 

 they run a rapidly fatal course — generally if 

 not always disseminated or miliary. That 

 is, tuberculosis did not become a human afflic- 

 tion until long after we began to cluster to- 

 gether in confined shelters — possibly not until 

 after we began to construct huts, " dugouts "' 

 and houses. 



The detailed data which prove the relation- 

 ship of tuberculosis and typhoid fever will 

 appear in American Medicine in January, 

 but this preliminary note is published as an 

 answer to the questions of Hazen and Sedg- 

 wick as to how we could explain the phe- 

 nomenon of a decrease of tuberculosis by the- 



