Xumber of cases. 
j Population, 1900. * 
Ratio of 
cases to 
popula- 
tion. 
Ages, years. 
Male. 
Female. 
Total. 
Male. 
Female. 
Total. 
20-24 _ _ J 51 
•28 
79 
13,774 
17,736 
31,510 
1- 398 
•>5-29 44 1 
07 
71 
13,345 
16,410 
•29,755 
1- 419 
30-34 . . _ .... -27 ' 
13 
40 
11,911 
12,857 
24,768 
1- 619 
3.5-39 . . 17 
10 
27 
10.409 
11,472 
21,881 ! 
! 1 - 810 
40-44_ _ . . 3 
4 
7 
8,679 
9,255 
17,934 
1-2,562 
4.5-49 _ _ _ _ _ _ S 
S 
16 
6,876 
7,750 
14,626 
1- 914 
50-.54. . . - . 2 
0 ' 
2 
6,371 
6,928 
13,299 
l-^,649 
55-59 __ . __ 2 
1 ^ 
3 
5,285 
5,001 
10, -286 i 
: 1-3,4-28 
60-64., . . - _ 1 2 
0 
2 
4,123 
4,078 ; 
8,201 ■ 
' 1-4,100 
65-69. ' 0 
0 
0 
2,431 
2,604 
5,035 
70-74 1 
1 
2 
1,611 
1,8-29 
3,440 
1-1,720 
75-79 _ . . 0 ■ 
0 
0 
796 
1,049 
1,845 
SO-S4 : 0 
0 
0 
351 
567 
918 
S-5-89 . J 0 
0 
0 
132 
206 
338 
1 
90-94 0 
0 
0 
26 
73 
99 
1 
95-99. . .. .... 0 
0 
0 
10 
29 
39 
' 
100 and nrer ..... n 
0 
0 
6 
14 
20 
Age unknown ... 0 
0 
0 
162 ' 
133 
295 
Total .... ... 304 
219 
523 
132,004 
146,714 
278,718 
The youngest j^erson affected at as '2 years and the oldest 73 years of 
age. As the cases occurred in 1907 and the census was held in 1900, 
the figures are not strictly comparable, but serve as a fair basis for an 
estimate. It will be noted that the largest number of cases propor- 
'tionate to population occurred among persons from 10 to II years of 
age. and the next largest among persons from 5 to 9. Thus, our 
studies for the two years show that the opinion usually held that 
typhoid fever is most prevalent among persons in early adult life 
(20 to 30 years) is not true for the District of Columbia, the disea^^e 
here being most preA’alent among children. As typhoid feAxr in 
children is frequently mild and irregular, many cases are not recog- 
nized. Therefore it is probable that more cases than the table indi- 
cates actually occur in persons under the age of 15 years. 
By decades, 103 of the cases were under 10 years. 171 between 10 
and 20. 150 between 20 and 30. 67 between 30 and 10. 23 between 10 
and 50, and 9 over 50. 
The rather large proportion of cases among children points espe- 
cially to two factors in the transmission of the infection of tAq^hoid 
feA’er — contact and milk. Large numbers of children from many 
households are in free and intimate association in playing, so that 
the chances of spread of infection among them by direct or indirect 
contact must be greater than among adults. 
Furthermore, mild and irregidar attacks of typhoid feA'er are known 
to occur with greater frequency in children than in adults, so that the 
spread of infection by contact from unrecognized cases among chil- 
dren must be correspondingly more frequent. 
