﻿REPORT ON CHOLERA IN MANILA. 415 



immune serum. This test, together with the examination of the mor- 

 phology and motility of the organism, was performed five or six hours 

 after the inoculation of the cultures and in case a negative result was 

 obtained, was repeated after from sixteen to twenty-four hours. Only 

 when positive reactions are encountered by this method can the diagnosis 

 be considered to be conclusive. In case of a negative result, a study of 

 the plate cultures which should previously have been prepared should 

 be resorted to. In some cases in which no agglutination of the organ- 

 isms which has been cultivated in this way by the enriching process 

 resulted, cholera spirilla were later isolated and identified by means of 

 plate cultures. The success of the peptone solution method in securing 

 a positive diagnosis obviously depends chiefly upon the number of cho- 

 lera spirilla which exist in the stool. 



A number of experiments in diagnosis were also carried on according 

 to the method advised by Dunbar 2 and by means of which an immediate 

 diagnosis of cholera may occasionally be made from the fasces. However, 

 it is worth while to undertake this method only with specimens of 

 excreta in which numerous organisms with more or less typical morphol- 

 ogy of the cholera spirillum are present. In stools of this nature the 

 reaction should always be attempted because of the immediate results 

 which may sometimes be obtained. Care must be taken to distinguish 

 pseudo-reactions, and only those cases should be considered as conclu- 

 sive in which the agglutination is distinct and well marked. The re- 

 action frequently failed in instances of undoubted cholera from which 

 pure cultures of the cholera spirillum were later isolated and identified. 

 The so-called cholera-red reaction, performed with peptone cultures and 

 with nitrite free sulphuric acid, could only be considered in determining 

 the diagnosis when a positive result was obtained, and even then the 

 reaction could only be regarded as confirmatory from a bacteriologic 

 standpoint. A single negative reaction, even though a satisfactory 

 peptone media had been employed, could not be looked upon as an 

 important argument against a positive diagnosis of the cholera organism, 

 since different strains were found to vary in this respect. Obviously, 

 the cholera-red reaction, unless performed with pure cultures of the 

 spirillum, is entirely untrustworthy and the results can not be depended 

 upon even as an aid in diagnosis. 



No experiments were performed with the specimens sent for diag- 

 nosis, with the object of differentiating by means of the blood-agar of 

 Prausnitz 3 the cholera spirillum from other cholera-like vibrous in 

 the stools, the agglutinative and bacteriolytic tests having by practical 

 experience proved to be satisfactory for clinical diagnostic purposes, 



2 Berl. Klin, Wchnsch. (1905), 42, 1237. 

 3 Berl. Klin. Wchnsch. (1905), 42, 561. 



