ASIATIC CHOLERA. 193 



containing large numbers of comma-bacilli. On the whole, 

 however, it is scarcely possible to insist upon a complete 

 analogy between the intoxication of guinea-pigs and cholera 

 as it appears in human beings. 



Bacteriologic Diagnosis of Cholera. If an attack of 

 disease characterized by the occurrence of profuse, rice- 

 water diarrhea, vomiting, decline of temperature, cramps in 

 the calves, etc., arouse suspicion of cholera a suspicion 

 that must be considered and investigated in every instance, 

 especially in travelers during the summer season, and par- 

 ticularly when cholera exists bacteriologic examination 

 of the stools is an absolute duty. The procedure in a 

 case suspected to be one of cholera is as follows : 



1. Microscopic Examination. Cover-slip preparations are 

 made with a flake of mucus from the feces, and stained 

 with dilute carbol-fuchsin solution. The diagnosis of 

 Asiatic cholera is rendered in the highest degree probable 

 if the vibrios form masses " in which the individual bacilli 

 all point in the same direction, so that an appearance is 

 created as if a small swarm of them, somewhat like fish in 

 a slowly flowing stream, are following one another"; or 

 if, " in addition to isolated bacteria presenting the appear- 

 ance of cholera-bacteria, only the bacterium coli is found. " 

 The probable diagnosis of cholera can be made microscop- 

 ically in about 50 per cent, of suspected cases, but in every 

 instance it should be confirmed by cultural investigation. 



2. Cultural Investigation. (a) Gelatin-plate Method. 

 Three gelatin-inoculations are prepared, in the usual man- 

 ner, from the feces, if possible from a flake of mucus, and 

 the inoculated culture-media are poured into three Petri 

 dishes ; these are kept at a temperature of from 22 C. 

 (71.6 F.) to 26 C. (78.8 R). If upon these plates 

 colonies are found after from fourteen to thirty or forty- 

 eight hours, with uneven, rough borders, strewn with bright 

 granules resembling fragments of glass, and presenting an 

 area of liquefaction, and if these colonies prove to be 

 constituted of commas, a high degree of probability is 

 given the diagnosis, and it is scarcely possible that the dis- 

 ease under consideration is any other than Asiatic cholera. 

 So far as is yet known, there occur in the human intestine 

 no vibrios other than the comma-bacilli that give rise to 

 colonies presenting the characteristics that have been de- 

 scribed. 



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