8 
Age. — The average age of the men in whom parasites were found 
was 37.75 years; of the uninfected cases, 47.9 years. The average 
age of those infected with hookworms was 32.8 years; with Trichuris, 
36.1 years; with Oxyuris^ 66 years; with Strongyl aides ^ 45.66 years; 
with Ascaris^ 41.5 years. 
Dividing the patients into classes according to age, we obtain the 
following results : 
Table 2. — Frequency of infection ivith regard to age of patients. 
Age (years). 
Number 
exam- 
ined. 
Hook- 
worms. 
Trichurig. 
Oxyuris. 
Strongy- 
loides. 
Ascaris 
himbri- 
coides. 
! Total, 
No. 
Per 
cent. 
No. 
i Per 
1 cent. 
No. 
Per 
cent. 
No. 
Per 
cent. 
No. 
Per 
cent. 
No. 
Per 
cent. 
18-30 
93 
- 
7. 53 
17 
18.28 
0 
0 
0 
i 0 
0 
0 
21 
25. 8 
31-50 
181 
1 
2. 17 
26 
i 11.13 
0 
0 
2 
1.09 
2 
1.09 
31 
18.12 
51 -f 
191 
1 
0.52 
5 
' 2.53 
1 
2.01 
i 
0.52 
0 
0 
11 
5. 67 
Unknown 
29 
3 
10.31 
1 6 
20.69 
0 
0 
0 
0 
0 
0 
9 
31.03 
Total ; 
500 
15 
3.00 
51 
10.8 
1 
0.8 
3 
0.6 
2 
0.1 I 
78 
15. 6 
a See footnote rf, table 1. 
The rate of infection decreases as the age of the patients increases. 
Heisig found similar results in Germany, though his percentages were 
higher and his patients included both men and women. 
Table 3. 
15 (18)-30 years. 
31-50 years. 
51 
-!- years. 
Number 
Infected. 
Number 
1 Infected. 
t 
Number 
Infected. 
exam- 
exam- 
exam- 
ined. 
No. 
Per cent. 
ined. 
No. 
Per cent. 
ined. 
No. 
Per cent. 
Heisig 
17 
/ 
11.5 
28 
9 
32.1 
23 
3 
13. 
Government hospital. 
93 
21 
25.8 
ISl 
33 
17.9 
191 
11 
5. 87 
Length of residence in the hospital. — Considering the amount 
of infection found with regard to the length of residence of the patients 
within the hospital, the results are as follows: Admitted within one 
year, 162 men; infected, 28 men, or 17.28 per cent. With from one 
to three years’ residence, 154 men; infected, 20, or 12.99 per cent. 
From three to eight years, 57 men; infected, 5, or 8.77 per cent From 
eight to fifteen years, 45 men; infected, 3, or 6.66 per cent. More 
than fifteen years, 71 men; infected, 7, or 9.86 per cent. 
The rate of infection decreases as the length of residence in the 
hospital increases, except in the class which had spent fifteen years or 
more in the institution, where the percentage rises. 
