BACTERIACE.E : THE BACILLUS OF DIPHTHERIA 2Q5 



antitoxin, and the amount of the latter which keeps the guinea- 

 pig alive for just four days, or, in other words, produces the same 

 effect as the standard unit, is known to contain one immunity 

 unit. In the United States, the Hygienic Laboratory at Washing- 

 ton furnishes standard antitoxin to manufacturers for this official 

 test and all marketed sera are tested by this method. 



Diphtheria antitoxin not only prevents the development of 

 diphtheria when injected in doses of 1000 units, but it also 

 exerts a marked influence as a therapeutic agent in diphtheria, 

 neutralizing the poison produced by the bacilli in the body of 

 the patient. It does not kill the bacilli but it nullifies their 

 chief offensive weapon, the soluble diphtheria toxin. Its value 

 in treatment of diphtheria is everywhere attested by clinical 

 evidence. The inflammation in the throat subsides and the 

 membrane disappears. The bacilli, however, may remain for a 

 considerable time. Local antiseptics may assist the natural 

 agencies of the body in their destruction. In some cases they 

 persist for months in spite of vigorous treatment. 



Certain untoward effects have followed the injection of anti- 

 diphtheritic serum. Sudden death has occurred in very rare 

 instances and skin rashes are rather common. These effects 

 are probably due to toxic substances set free in the parenteral 

 digestion of the foreign protein and are doubtless of the same 

 general nature as the phenomenon of anaphylaxis. Since the 

 introduction of the concentrated antitoxin fatalities have become 

 exceedingly rare or have been entirely eliminated. The serum 

 rashes and cases of nervous shock do occur, especially in asthmatic 

 individuals and in those who have received a previous injection 

 of horse serum. In these persons it is well to give a minute 

 quantity, 0.2 c.c., of the serum as a preliminary injection, wait 

 two or three hours and then give the full dose. The danger of 

 serious reactions due to anaphylaxis may thus be avoided. 1 



Bacillus (Bacterium) Xerosis. This organism occurs on the 

 normal mucous membranes, particularly the conjunctiva. It 



1 Vaughan: Amer. Journ. Med. Sciences, 1913, Vol. CXLV, pp. 161-177. 



