DIPHTHERIA ANTITOXIN 429 



Example. Stage 2. 



ifa c.c. Antitoxic Serum to be tested + -27 c.c. Toxin . Guinea-pig alive fifth day. 



5-5-75- C.C. ,. ,, i, ,, ,, 



Tfc C.C. , ,, died fourth day. 



^ c.c. . died first day. 



/. The mixture of ^ c.c. of Antitoxic Serum +'27 c.c. Toxin, killing guinea- 

 pig in four days, contains 1 M.L.D. 



' innr c - c - Antitoxic Serum = 1 Ehrlich unit. 



/. 1 c.c. = 300 Ehrlich units. 



4. The Use of Antitoxin. The antitoxin is now ready for injection 

 into the patient who has contracted diphtheria, and in whose blood 

 toxins are in the ascendency, and under which the individual may 

 succumb. They are injected in varying doses, as we have already 

 pointed out. As large a dose should be given as practicable. A 

 common first dose varies from 2000 to 5000 units. For prophylactic- 

 purposes a smaller dose is administered (500, and for children under 

 two years of age, 300 units). Early administration is of great 

 importance. The flank between the crest of the ilium and the last 

 rib and the lower part of the abdomen are generally selected as the 

 sites of injection, but any region with loose subcutaneous connective 

 tissue is suitable. The injections should be subcutaneous. In 

 performing the injection strict asepsis must be observed. The 

 syringe must be well washed and boiled before use. The skin must 

 be well cleansed with soap and water, and afterwards treated with an 

 antiseptic such as a 1 in 1000 corrosive sublimate solution, or 1 in 

 20 carbolic acid solution. The antitoxin of diphtheria has been used 

 on various recent occasions as a prophylactic in outbreaks of the 

 disease, and it is now considered as one of the practicable means for 

 controlling an epidemic. Antitoxin inoculation played a greater or 

 less part in the checking of diphtheria outbreaks at Cambridge,* 

 Colchester,-)- Kempston,| and other places. In the Cambridge 

 outbreak antitoxin was supplied free for prophylactic use in the case 

 of those who had come into contact with actual cases of diphtheria, 

 or where those who, not being ill, were known by bacteriological 

 examination of the throat to be harbouring the diphtheria bacillus. 

 Thus free bacteriological examination of the throat of suspected or 

 known "contacts" was first carried out. In the cases yielding 

 positive results antitoxin was injected. At Cambridge 500 units of 

 antitoxin were given in such contact persons; at Kempston 1000 

 units was the dose. The general result is that mortality has been 

 lessened, and that in fatal cases there has been a considerable 

 lengthening of the period of life. Moreover, the whole clinical 

 course of the disease is greatly modified, and its severity reduced. 



* Jour, of Hygiene, 1901, vol. i., pp. 228 and 487. 



t Ibid., 1902,' vol. ii., p. 170. 



$ Report on an Outbreak of Diphtheria at Kempston, p. 21. 



