134 APPLIED IMMUNOLOGY 



Secondary Stage. — The reaction is positive in 

 practically all cases of secondary syphilis, and is there- 

 fore of the greatest value in making the diagnosis of 

 atypical cases. In this stage, too, we usually find the 

 strongest reactions. 



Tertiary Stage, — In tertiary syphilis a positive 

 Wassermann reaction is obtained in 80 to 90 per cent, 

 of cases. A negative reaction in this stage therefore 

 does not have quite the same significance as in sus- 

 pected secondary syphilis. Medium and weakly posi- 

 tive reactions are more frequent here than in the 

 secondary stage. 



Latent Syphilis, — By latent stages are meant 

 periods in which all symptoms disappear for a time, 

 either spontaneously or as a result of treatment, but 

 in which, as shown by the Wassermann test, the spe- 

 cific reaction between the spirocheetse and the tissues 

 is still going on, indicating therefore that the disease 

 is not eradicated. It has been found that persons in 

 this stage, although exhibiting no symptoms, yet are 

 capable of infecting others, and themselves are liable 

 to develop later manifestations of the disease. It is 

 estimated that about 50 per cent, of latent syphilitics 

 give a positive Wassermann reaction. It is difficult to 

 estimate this percentage, because we cannot always 

 say whether a given case having a negative Wasser- 

 mann reaction is cured or merely in the latent stage. 



