630 
The Philippine Journal of Science 
Table 2. — Age incidence. 
Years. 
14 to 20 
20 to 30 
30 to 40 
40 to 50 
50 to 60 
60 to 70 
70 to 80 
Total 
Cases. 
40 
80 
19 
9 
8 
8 
0 
• 164 
Age in years. 
50 60 70 BO 
Table 2 shows that the greatest number of cases occurred in 
young adults from 20 to 30 years of age. This observation is 
similar to Shiga’s (9) findings, in 
Japan, who also observed a great 
number of cases between the ages 
of 20 and 30 years. A graphic 
representation of age incidence 
is shown in fig. 1. 
SEASONAL INCIDENCE 
The disease occurs throughout 
the year. In my series it pre- 
vailed in greatest number in 
July, August, and September. 
The incidence is shown in Table 
3 and graphically presented in 
fig. 2. 
Table 3. — Seasonal incidence. 
Fig. 1. Illustrating the age incidence 
by decades. 
Month. 
Cases. 
January 
3 
February 
2 
March 
1 
April 
8 
May 
7 
June 
9 
July 
39 
August 
42 
September 
40 
October 
8 
November 
2 
December 
3 
A study of Table 3 indicates that there was a gradual in- 
crease in the number of cases admitted to the hospital from 
April to September, the largest number having occurred during 
