540 A MANUAL OF BACTERIOLOGY 



heated vaccine without phenol is the most efficient and 

 that next in order come (a) living culture, (6) a modifica- 

 tion of Strong's vaccine, (c) a sensitised vaccine. Castel- 

 lani has introduced the use of a polyvalent vaccine 

 containing typhoid, paratyphoid A and B, and cholera. 



The most extensive statistics of the value of anti- 

 cholera inoculation are those of the Balkan War, 1913-14. 

 Of 114,803 men, 8,968 were not inoculated and the inci- 

 dence of cholera among them was 93 cases per 1,000 ; 

 14,613 were inoculated once, and the incidence was 42 

 per 1,000 ; 91,224 were inoculated twice, and the inci- 

 dence was 7 per 1,000. The case-mortality was among 

 the uninoculated 27-5 per cent., among the once-inocu- 

 lated 12-2 per cent., among the twice-inoculated 10-2 

 per cent. 



Clinical Diagnosis 



1. Prepare films from the stool and stain with dilute carbol 

 fuchsin. If on examination large numbers of curved rods lying 

 in groups parallel to one another are observed, the diagnosis of 

 Asiatic cholera may be made with some degree of certainty. 

 (Single, or a few, vibrios are of no diagnostic significance ; they 

 may occur in normal and diarrhoea stools. The presence of 

 numbers of vibrios having the " fish -in -stream " arrangement is 

 also not absolutely characteristic.) 



2. (a) Inoculate about 40 c.c. of Dunham's peptone water 

 contained in a small Erlenmeyer flask with 1 to 2 c.c. of the 

 stool. Incubate at 37 C. 



(6) After six hours' incubation make films and hanging-drop 

 preparations and, if necessary, inoculate ? second flask of peptone 

 water from the surface fluid of flask No. 1. Incubate for eight 

 to twelve hours. 



(c) At the end of incubation period, from the surface of the 

 fluid make films and hanging-drop preparations, and plate out 

 a loopful on Endo- or Conradi-agar medium. Incubate the plates 

 until growth can be distinctly seen usually eight to twelve hours. 

 Search for and examine suspicious colonies. If vibrios be found, 

 test for agglutination by taking up a trace of the colony on a 



