372 THE ALCALIGENES—DYSENTERY— TYPHOID GROUP 
obtained them in 5 out of 6 cases. Both Neiifeld and Richardson 
emphasize the importance of incising several spots. The technique 
developed by Richardson is as follows: The skin over several rose 
spots is cleaned as for a surgical operation, and then frozen by a 
spray of ethyl chloride. This procedure driAes out most of the blood, 
as well as making the operation practically painless. A small incision 
is then made with a sterile knife and the substance of the rose spot 
is removed with a small skin curette and at once placed in 0.1 per cent 
glucose broth, and incubated for eighteen to twenty-four hours. 
The identification of the bacilli which develop in the broth is made 
by the usual cultural and agglutination reactions. 
2. Isolation of Typhoid Bacilli from the Urine. —Typhoid bacilli 
have been found in the urine in from 25 to 35 per cent of the cases 
examined. Such urines frequently contain albumin. The organisms 
do not, as a rule, appear until the third week of the disease, conse- 
quently their isolation is of comparatively little value diagnostically, 
although their recognition is of great importance for the prevention 
of secondary cases. The organisms may exist in the urine for a few 
weeks after convalescence. Rarely they persist for months or very 
rarely for years after recovery. F'requently their presence is not 
manifested by clinical symptoms, but occasionally persistent cystitis 
may be caused by their continued growth in the urinary bladder. 
Usually the bacilli present in the urine are found in pure culture. 
Occasionally colon bacilli are found either in association with typhoid 
bacilli or even in pure culture after the typhoid bacilli have disappeared. 
3. Isolation of Typhoid Bacilli from F^fe^.— Typhoid bacilli are 
usually found in pure culture or nearly pure culture in the blood, and, 
if the proper precautions are observed, in the urine as well. In the 
feces, on the contrary, they are usually in the minority and their 
isolation presents certain difficulties. It has been claimed by many 
authorities that typhoid bacilli are not found in the feces in demon- 
strable numbers, at least until about the middle of the second week. 
Klinger^ has collected statistics from 804 contact cases which indicate 
the danger of infection from feces even before the development of 
clinical symptoms. 
Secondary Cases Infected from Primary Cases. 
First week of incubation period 33 
Second week of incubation period 150 
First week of disease 187 
Second week of disease 158 
Third week of disease 116 
Fourth week of disease 59 
Fifth week of disease 34 
Sixth week of disease 22 
Seventh week of disease 14 
Eighth week of disease 16 
Ninth week of disease 15 
' Public Health Reports, 1911, 26, 319. 
