138 APPLIED IMMUNOLOGY 



The Wassermann reaction has shown that a high 

 percentage of cases of aortic disease and aneurism are 

 syphilitic in origin. 



Effects of Treatment on the Wassermann Reac- 

 tion, — The Wassermann reaction is markedly in- 

 fluenced by treatment. In a syphilitic undergoing 

 treatment with mercury and particularly salvarsan, 

 the reaction may rapidly be reduced from strongly 

 positive to negative. As a guide or measure of the 

 effects of treatment, therefore, the Wassermann reac- 

 tion plays almost as important a role as it does in diag- 

 nosis. True biological antibodies, such as for instance 

 occur in typhoid fever as determined by the agglutina- 

 tion reaction, may persist in the blood for months and 

 even years after the disease has been eradicated. On 

 the other hand, the evidence of the Wassermann reac- 

 tion shows that the substances taking part in it disap- 

 pear from the patient's body very shortly after the 

 destruction of the syphilitic virus by treatment, or 

 when the virulence of any remaining spirochset^ is 

 much diminished. 



In the primary stage, if treatment by salvarsan or 

 neosalvarsan be instituted as soon as the diagnosis is 

 made (by dark field illumination), the Wassermann 

 reaction may never become positive and secondary 

 symptoms may never appear. With every day that 

 treatment is delayed, and especially after the Wasser- 



