11 
The pricking of the ear lobe or finger tip to obtain a drop of blood 
for the Widal test causes so little pain that, in frequent instances, a 
sleeping cliild will not be awakened by the procedure. The Widal 
tests yfill give positive results at some time in the course of the illness 
for about 95 per cent of cases. Positive results are rarely obtained 
before the tenth or twelfth day of fever, and this lateness of the 
development of the agglutinating property of the blood prevents the 
Widal test from being of much aid in early diagnosis . 
The puncture of a vein at the elbow joint, in order to obtain a few 
cubic centimeters of blood for bacteriological examination by culture, 
causes a slight amount of pain, it is true, but when the operation is 
done properly it is entirely free from danger and causes no more 
distress to the patient than does the application of a swab to the 
throat in order to obtain cultures in cases of suspected diphtheria. 
The great advantage of the blood-culture method is that it gives in 
the earliest stages of the illness positive results and maximum 
information. 
In about 90 per cent of cases in the first week of fever the blood 
culture test will demonstrate the typhoid bacillus, usually in pure 
culture. The later in the attack the blood is taken the less are the 
chances of demonstrating the organism. Thus Heinrich Kayser,® 
working in Germany, obtained positive results in 96 per cent of 
cases examined in the first week, in 65 per cent examined in the 
second week, in 42 per cent in the third week, and in 35 per cent in 
the fourth week. Kayser took only 2.5 c. c. of blood for each 
examination. 
Since beginning our investigations of typhoid fever here in 1906 
we have offered to the physicians of the District of Columbia the 
facilities of the Hygienic Laboratory, U. S. Public Health and 
Marine-Hospital Seiwice, to assist them in the diagnosis of suspected 
cases. So far, comparatively few requests for blood cultures have 
been received. It appears that the value and ease of application of 
this test are not generally appreciated. 
METHOD OF INVESTIGATION. 
In the study of the cases this year the following form was used and 
all facts called for by this form were carefully investigated for each 
case. The form is the same as the one used in 1907 : 
Typhoid Fever Case Card. 
Date of investigation, . Case Xo. . 
Name, . 
Age, . Color, . Sex, . Xationality, . 
Probable date of onset, . Date definite symptoms, . 
Xame and address of physician, . 
o- Munch, med. Woch., 1906, p. 823. 
