H YPER.SKXSITIVENESS 523 



Incidence of Tuberculosis Determined at Autopsy.— In 1917 



Opie reported evidence of tuberculosis in 8.3 per cent of infants 

 dying within the first two years of life, 44 per cent in children 

 dying between the ages of two and ten years, 66.7 per cent for ages 

 ten to eighteen years, and 100 per cent for those dying at later 

 ages. These percentages include many cases of healed tuberculosis 

 as well as cases that showed activity. In 1927 Opie and Aronson 

 studied material from 169 bodies that showed what appeared to be 

 healed lesions. By means of guinea pig inoculation they found 

 that 20 out of 29 apparently healed lesions contained living 

 tubercle bacilli. 



In a later discussion of the epidemiology of tuberculosis, Opie 

 (1932) calls attention to the continued high incidence of tuber- 

 culosis in Philadelphia and to the appalling number of serious 

 tuberculosis infections revealed by anatomical studies. He states 

 that such studies made in St. Louis and Philadelphia indicate that 

 one out of every six white adults who die from diseases other than 

 tuberculosis have partially caseous lesions at the apices of one or 

 both lungs. He seems to interpret the diminution of the death 

 rate from tuberculosis as indicating that the infection is now 

 following a more benign course than formerl3^ Opie points out 

 that the skin test is the most delicate method of detecting infection, 

 although it does not differentiate between latent and manifest 

 tuberculosis. 



Robertson's Anatomic Studies. — On the other hand, the studies 

 of Robertson (1933) and also of Terplan (1934) apparently sup- 

 port the statement of Long that the incidence of tuberculosis is 

 less than it was twenty-five years ago. Robertson reviews the 

 series of 3,306 autopsies done at the Mayo Clinic over a period of 

 six years (1926-1931) to determine the incidence of tuberculosis. 

 He found tuberculous lesions present in 2,064, or 62.43 per cent, 

 of the bodies examined. As a result of histological studies he con- 

 cludes that the lesions in 1,725 of these cases weie healed and that 

 there is evidence of active tuberculosis in 134, or 4.05 per cent. 

 The incidence of active tuberculosis for the various age groups 

 is interesting. For the first three decades of life it was 2.94, 6.71 

 and 6.84 per cent, respectively. For the decades between 30 and 

 70 years it was 3.78, 3.17, 4.47, and 3.99 per cent, respectively. 



