390 INVESTIGATION, ETC., OF MILK-BORNE EPIDEMICS 



fifteen minutes ; the remaining 3 showed a complete reaction 

 within thirty minutes. The dilution varied from i in 10 to i in 

 20, but did not exceed this. The clinical course of every one of 

 these 26 cases determined them to be typhoid." 



Thursfield ^ has shown that the Widal test is as reliable in 

 children as in adults. 



Preventive inoculations. — As we have seen bacteriology has 

 materially assisted in the checking of epidemics partly by diagnosis 

 and partly by preventive inoculation. The latter is illustrated in 

 various diseases such as small-pox (vaccination), rabies (Pasteur's 

 treatment), cholera, typhoid, and plague (inoculations), and 

 diphtheria (antitoxic serum). It will be sufficient if typhoid fever 

 and diphtheria, the two diseases more particularly conveyed by 

 milk, are alone referred to in this place, and that only in so far as 

 applicable to the prevention of epidemics. 



The vaccine employed in the anti-typhoid inoculation was first 

 made by Professor Wright of Netley.^ It has been used to a large 

 extent among soldiers in India and South Africa with some 

 measure of success, and it has been applied in an epidemic of 

 typhoid fever.^ 



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 con- 

 trolling an epidemic. Antitoxin inoculation played a greater or 

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

 Colchester,^ Kempston,^ and other places. In the Cambridge out- 

 break 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. It is unnecessary to dogmatise as to 



1 Brit. Med. Jour., 1901, vol. ii., p. 596. 



2 For the methods which have been employed in the preparation of anti- 

 typhoid vaccine, see Brit. Med. Jour., 1900, vol. i., pp. 122-129. 



3 Brit. Med. Jour., 1901, vol. ii., p. 1226. 



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



^ Ibid., 1902, vol. ii., p. 170. 



' Report on an Outbreak of Diphtheria at Kempston, p. 21 (Newman). 



