I08 CLINICAL BACTERIOLOGY AND HEMATOLOGY 



9. Do not fall into the mistake of thinking that because a 

 patient gives a positive Wassermann reaction he may not have 

 some disease other than syphilis in addition. A history of syphilis 

 is very common in cases of cancer of the tongue, and a positive 

 Wassermann reaction hardly tells against such a diagnosis. 



ID. No disease other than syphilis indigenous to this country 

 gives a positive Wassermann reaction except occasionally scarlet 

 fever, in which it only persists for a short time. A positive reac- 

 tion is therefore practically conclusive. In foreign countries 

 there are a few other diseases which cause it, such as leprosy and 

 framboesia, and these should be borne in mind in the case of a 

 patient who has travelled. 



CHOLERA 



The diagnosis of cholera can only be made on clinical grounds 

 alone during an epidemic, as other diseases present almost 

 identical symptoms and course. The importance of making a 

 correct diagnosis arises less from the interests of the patient than 

 from those of the general public ; if the case is one of true Asiatic 

 cholera, the sanitary authorities must be notified and the fullest 

 precautions taken to prevent the spread of the disease. In all 

 suspicious cases a quantity of the rice-water stools (in a bottle 

 sterilized by boiling or by dry heat and securely packed) should be 

 forwarded at once to a public laboratory. Meanwhile the 

 diagnosis may be established with a fair amount of certainty by 

 the following simple tests : 



1. Take a platinum loopful of the dejecta and spread it in a 

 thin film on a clean slide ; dry, fix, and stain with carbol fuchsin 

 for three minutes ; wash, dry, and mount. 



2. Prepare another film and stain by Gram's method. 



Examination of the Films. 



The spirillum of Asiatic cholera is about half as long as a 

 tubercle bacillus, or rather longer, and much thicker. It is 

 slightly curved : hence the name of the " comma bacillus." It 

 looks very like a caraway seed (Plate II., Fig. 5). 



In the carbol fuchsin specimen vast numbers of these curved 

 rods will be seen ; probably few other organisms, if any, will be 

 present if the case is one of true cholera. Two or more rods 



