BACILLUS DIPHTHERIA 577 



tant thing is to correct pathological conditions of the nose and throat by 

 the correction of a deviated septum or the removal of tonsils and ade- 

 noids, whenever necessary. Added to this, sunshine, cleanliness and 

 the cure of chronic catarrhal inflammation are probably more important 

 than any kind of antiseptic treatment. 



The detection of carriers can easily be carried out on a large scale 

 by a relatively small force of bacteriologists. It requires a large supply 

 of sterile swabs and Loeffler's medium, and wholesale cultures can be 

 taken on a group as large as entire infantry regiments at war strength 

 without too great an expenditure of energy. 



The prevention of diphtheria for all these reasons falls into a very 

 logical system of procedure. Whenever diphtheria breaks out in a 

 school, institution, military unit, factory unit, etc., etc., the first thing 

 to do is to make a thorough inspection and immediately institute pre- 

 cautions against the transmission of mucus from one individual to 

 another. This will imply supervision of the kitchen, food preparation, 

 dish washing, prohibition of spitting, isolation of individuals who are 

 coughing and hawking or suffering from severe catarrhal inflammations; 

 cleanliness of sleeping quarters and mess halls, inspection of the entire 

 group, and the taking of throat cultures; segregation of those that show 

 positive cultures; especially attention in this regard, and repeated 

 culturing of kitchen personnel and food handlers ; Schick reactions upon 

 the entire group, with prophylactic immunization (preferably by the 

 active method), of those with positive Schick reactions; subsequent 

 attention to chronic carriers. These precautions are simple and 

 applicable with minor modifications to any kind of group in which 

 diphtheria appears. 



Shick Reaction. The studies of Roemer and others have shown 

 that the blood of the majority of normal adults contains a small amount 

 of diphtheria antitoxin. This normal antitoxin probably accounts for 

 resistance of many individuals to diphtheria. Its presence may be 

 very easily detected by means of the Schick reaction. A standardized 

 diphtheria toxin is diluted in normal saline so that 0.1 c.c. of the solu- 

 contains Vso M.L.D. for a guinea-pig. This amount is injected intra- 

 cutaneously. If the blood of the subject has less than 1 / 30 unit of 

 antitoxin per cubic centimeter, a positive reaction appears in twenty- 

 four to thirty-six hours, which consists in a slight infiltration of skin 

 surrounded by a red areola, 1 to 2 cm. in diameter. A negative reaction 

 indicates that sufficient natural antitoxin is present to protect the indi- 

 vidual against diphtheria, although he 'may nevertheless harbor the 



