CHAPTER XII. 
DISEASES CAUSED BY UNKNOWN MICRO¬ 
ORGANISMS. 
Under this head are placed a number of diseases 
in which no micro-organism has been definitely demon¬ 
strated as the cause. 
Scarlet Fever. 
The infection almost always occurs from direct 
contact; entering the sickroom may be exposure 
enough to cause the disease. Objects which the patient 
has touched will transmit the infection such as linen, 
clothing, furniture, and playthings. Physicians and 
nurses sometimes carry the infection, although they 
themselves may not be affected. Milk has been known 
to carry the infection and cause serious epidemics. 
The milk in such cases is infected at the dairy by 
someone who has the disease. The infection may be 
transmitted at any time during the disease by the secre¬ 
tions from the nose and mouth and from the skin, dur¬ 
ing the period of desquamation. 
In order to prevent it from spreading, the sick 
room in private homes should be as far away as pos¬ 
sible from the room occupied by other members of the 
family. Admission to the room should be denied to 
everyone except the physician and the nurse. The 
physician should wear a gown and cap when entering 
( 126 ) 
