i860 



THE DYSENTERIES 



Good scavenging and strict hygienic laws are necessary to prevent 

 the breeding of flies, and if an epidemic of dysentery occurs, a 

 special crusade against the common house-fly, if not begun before, 

 should at once be undertaken, as has been done for other reasons 

 in Liverpool and elsewhere, especially in America. 



Dust should be diminished in the warm dry weather by the 

 efficient watering and brushing of the roads of towns, and in this 

 water some cheap disinfectant such as permanganate of potash 

 should be used, especially for the more important streets. 



The drinking-water of all large towns should be filtered, though 

 it must be admitted that this alone is not a sufficient safeguard 

 against a water-borne epidemic. 



Vaccination. — Owing to bacterial dysentery being due to several different 

 bacilli, and owing to the fact that the Shiga-Kruse bacillus is very toxic the 

 preparation of an efficient vaccine giving a not too severe reaction is difficult. 



Broth Cultures Vaccine- — Antidysentery vaccines prepared with broth 

 cultures should never be used, as they give rise to an extremely severe local 

 reaction, with at times abscess formation. 



Peptone Water Vaccine. — Castellani, in 1904, prepared a mixed peptone 

 water vaccine which gave fairly satisfactory results. The preparation was 

 as follows: — The Shiga-Kruse bacillus and three other species of dysentery 

 bacilli were grown in peptone water tubes for three days at 35° C. They 

 were kept for an hour at the temperature of 55°-6o° C, and then mixed, three 

 parts Shiga-Kruse and one part of each of the others. Of the resulting mixed 

 vaccine i c.c. (sometimes J c.c.) was injected, the inoculation being repeated 

 after a week or two. The reaction was not severe. Later Castellani prepared 

 the same vaccine without heating, adding simply -| per cent, carbolic. Accord- 

 ing to Castellani, the very much less marked reaction noted than when using 

 broth vaccines, is not merely due to the fact that peptone water cultures 

 contain fewer bacilli than broth cultiires. 



Carbolized Emulsion Mixed Vaccine.- — Since 191 2 Castellani has used in 

 Ceylon a carbolized mixed vaccine containing B. dysenteries Shiga-Kruse, 

 Hiss-Russell Y, original Flexner, Ceylon Flexner-like No. i, Ceylon Flexner- 

 like No. 2. The preparation of this mixed vaccine is as follows: — The indi- 

 vidual vaccines are prepared by making emulsions from twenty-four hours' 

 old agar cultures in normal salt solution (0-75 per cent.), to which 0*5 per 

 cent, of carbolic acid has been added, and the individual vaccines are standard- 

 ized in such a way as to contain per c.c. 1,000 million germs. These 

 mono vaccines so standardized are mixed in equal parts, so that i c.c. of the 

 mixed vaccine will contain 125 millions of each of the organisms used. Of this 

 mixed vaccine 0*5 to 0*6 c.c. is given hypodermically the first time, and the 

 same or double the amount after a week. Agglutinins generally develop for 

 all the inoculated germs, but their amount is not high, and may be inconstant 

 and irregular, but the same may be said of simple monovaccines, Shiga, 

 Flexner, etc. 



It is essential to prepare the vaccine with strains which, though rich in 

 antigen, are only slightly virulent. It is extremely rare to come across such 

 a strain of Shiga-Kruse. A large series of strains of this species are inoculated 

 into rabbits, and the least virulent, provided it is rich in antigen, is kept 

 permanently as a stock culture to prepare the vaccine. 



Combined Carbolized Dysentery and Typhoid and Para A and Para B Vaccine. 

 — This vaccine has been prepared by Castellani, in 1013, following this 

 technique : — The individual vaccines are prepared by making emulsions from 

 twenty-four hours' old agar cultures in normal salt solution (0'75 per cent.), to 

 which ^ per cent, carbolic has been added. The monovaccines are then 

 standardized as follows: — Typhoid vaccine 4,000 millions per c.c, para A 

 1,000, para B 1,000, Shiga 1,000, Flexner 1,000, Hiss-Russell Y 1,000, Flexner 

 Ceylon (No. i) 1,000, Flexner Ceylon (No. 2) 1,000. The monovaccines are 



