INTESTINAL WORMS IN TYPHOID FEVER. 
211 
Age of persons. 
Number 
examined. 
1 
V hip worm infections. 
I 200 cases of ty- 
phoid, 1906, ar- 
ranged by ages. 
Total cases of ty- 
phoid, 1906, ar- 
ranged by ages. 
Number. 
Per 100 
persons. 
Percent. 
of cases. 
Number 
of cases. 
Per cent. 
Under 15 vears 
123 
16 
13.01 
55 27.5 
271 
31.3 
15 to 30 vears 
572 
50 
10.49 
095 47.5 
a 406 
46.9 
31 to 50 vears 
1,341 
116 
8.65 
&42 , 21.0 
& 165 
19.0 
Over 50 years 
1,289 
60 
4.65 
! c7 1 3.5 
c24 
2.8 
Unknown . 
1 , 
: 1 
“ 15 to 29 years, inclusive. & 30 to 49 years, inclusive. c 50 years and over. 
At the right of the above table, in their respective age groups, 
are given the number of cases of typhoid examined this summer for 
whipworms, and the total number of cases studied by the board. 
The percentages of the two t}'phoid groups (200 cases and total cases) 
vary slightly, but not sufficiently to indicate that the 200 cases form 
an unfair basis for comparison. 
If whipworms form the common inoculating agent of t^^hoid, it 
is not unreasonable to expect that there should be some general par- 
allel between the age groups of typhoid and of whipworm infection. 
From the above table it will be seen that the maximum t^'phoid age 
group (15 to 29 years) of the cases we examined does not correspond 
with, the maximum group (under 15 years) of wliipworm infection 
for this climate; further, while there is a decrease in both typhoid 
and in whipworms in the next two age periods (31 to 50 years, and 
over 50 years) this decrease is not even approximately parallel. 
Thus typhoid and the wliipworm infections compared on basis of 
ages of patients examined in tliis laboratory do not agree in the age 
groups of highest infection, while the percentages in the remaining 
groups are not even approximate; hence, from this point of wew, the 
theoiA^ under discussion receives no support from the present inves- 
tigation. 
The comparison made in the foregoing is in so far open to objection 
that in the case of whipworm infection the percentages represent a 
comparison of the infected persons with the total number of persons 
in the different age groups; while in the ti^hoid cases the percent- 
ages of infection represent a comparison of the number of patients of 
any given age group with the total number of patients. Thus the 
comparison is not mathematically exact. Nevertheless, this objec- 
tion is not so serious as might at first be assumed for the statistics 
on worms give the mathematical probabilities of infection for a given 
person in the respective age group; and since, under normal con- 
ditions, the proportions in inhabitants ivill decrease from the youngest 
to the oldest age group, since further (from the standpoint of the 
verminous theory) a greater number of persons under 15 years would 
