484 | ANNUAL REPORT SMITHSONIAN INSTITUTION, 1944 
ment in the tuberculosis picture has occurred is, of course, true. Our 
chances of dying of tuberculosis are now computed at a much more 
favorable level. It is also of interest to note that the percentage of per- 
sons tuberculin positive has been falling. For instance, one of the 
earliest reports on the results of tuberculin testing of a student group 
was based on a study conducted at the University of Minnesota in 1928. 
Thirty-one percent of 2,000 students were found to be tuberculin posi- 
tive. In 1941-1942 only 17 percent of 5,481 students were positive. 
Thus in 18 years there was a reduction of 45 percent in the number of 
tuberculin reactors. Similar information gathered from school surveys 
all over the country is much more significant than may on first thought 
occur to one. Weare fast becoming a nation of unsensitized individuals 
with respect to tuberculosis. There has long been a considerable school 
that has maintained that sensitization in the sense of tubercularization 
without progression is protection. What, they ask, will be the outcome 
as more and more tuberculin-negative children become adults and first 
meet the tubercle bacillus under wartime and reconstruction condi- 
tions? It is possible that the medical-school tuberculosis problem may 
cast light upon this matter, but before that point can be presented it is 
logical to consider the effect of war on tuberculosis morbidity and 
mortality. 
What was the effect on the tuberculosis rate of World WarI? Dr. 
Long describes the situation in Europe by observing: “After years 
of continuous drop, the rate began rising in 1915 and by 1918 had 
reached a figure in all countries about 25 percent higher than at the 
beginning of the war.” Wolff has described the privations of the 
period as “ an involuntary mass experiment . . . of more epidemio- 
logical importance than endless theorizing on the pathology of tuber- 
culosis.” These statements may be amplified in the words of an August 
1941 article in the Statistical Bulletin of the Metropolitan Life In- 
surance Co., in part as follows: 
The experience of the World War of 1914-18 affords an indication of what 
is likely to occur. None of the belligerent countries escaped an increase in 
tuberculosis then, and practically all of the neutral countries of Europe suffered 
either an increase in tuberculosis or a slowing up of the prewar rate of de- 
cline. The most reliable data for the period relate to the trends among women 
and children in England and Germany. Among English women the mortality 
from pulmonary tuberculosis rose steadily during the war to a peak in 1918, 
when it was over 25 percent higher than in 1913. Among German women the pul- 
monary tuberculosis death rate rose slowly at first, but after 1916 the increase was 
very rapid, so that by 1918 the rate was nearly 75 percent above that of 1913. 
Indeed, in Germany the death rate from tuberculosis among women did not 
return to the prewar level until 1921; and this improvement was not main- 
tained for a few years following. The rate of increase among German females 
was greatest at ages under 20 years. Among children the rate in 1919 was 
even higher than during the war. 
