510 SYPHILIS 



this point is necessary. As mentioned above, the spirochsete 

 pallida has been found in the lesions in monkeys, Metchnikoff 

 and Roux obtaining positive results in more than 75 per cent, 

 of the cases, and it is to be noted that here also the organism 

 has been found deep in the substance of the papules, un- 

 accompanied by any other organisms. It is also to be noted 

 that the blood of infected apes after a time gives the Wasser- 

 mann reaction. 



Serum Diagnosis Wassermann Reaction. The method of 

 applying this test has already been given (p. 131); we have now 

 to consider the results of its application. There is general 

 agreement amongst workers at the subject that the test affords 

 by far the most reliable means of diagnosis of the disease ; and 

 on comparing the results obtained it will not be an overestimate 

 to say that a positive result may be obtained in at least 90 per 

 cent, of cases where there is evidence of active general infection. 

 The reaction generally appears first on the fifteenth to thirtieth 

 day after appearance of the sore, and then gradually becomes 

 more marked ; during the period of secondary manifestations it 

 is practically always present ; in the tertiary stage with active 

 manifestations a positive result is only a little less frequent. As 

 the disease becomes inactive or is cured the reaction may disappear, 

 but it is to be noted that disappearance of the reaction after being 

 present does not necessarily imply cure of the disease. It may 

 only have become latent, and on its becoming once more active 

 the reaction may re-appear. Energetic treatment with mercury 

 may also diminish or annul the reaction ; in fact, its presence 

 and intensity would appear to be definitely related to the activity 

 of the syphilitic lesions. A positive reaction is also present in 

 the large majority of cases of general paralysis and of tabes, and 

 may be given by the cerebro-spinal fluid as well as by the blood 

 serum in such cases. As regards other diseases, a positive 

 reaction has been recorded as occurring in leprosy (p. 304) and 

 sleeping-sickness and also in yaws, but apart from these diseases 

 it is practically never met with. At present little can be said in 

 explanation of the Wassermann reaction. It seems to depend 

 on the interaction of lipoidal substances in the extract with 

 proteins in the serum, which are apparently contained in the 

 globulin fraction ; but we know nothing as to why this peculiar 

 modification of the serum should be present in syphilis. It is 

 now generally considered that it does not depend on the presence 

 of an anti-substance (immune-body), which in association with 

 the antigen (the spirochaite) fixes complement. 



