THE WASSERMANN REACTION 609 



leprosy, yaws, malaria, leishmaniasis and trypanosomiasis 

 be excluded. 



The Wassermann reaction is positive in all cases in the 

 primary stage of syphilis, though it does not become mani- 

 fest until at least a fortnight, usually from three or four to 

 six weeks, after infection. It is similarly positive in all cases 

 during the secondary stage ; in the tertiary stage, some 

 80-90 per cent, of the cases are positive. In para-syphilitic 

 affections, e.g. tabes and general paralysis, some 50 per 

 cent, of the cases are positive. In latent intervals, i.e. when 

 there are no active symptoms, some 50 per cent, of the cases 

 are positive. In cases with lesions of the nervous system, 

 the cerebro-spinal fluid frequently yields a positive 

 Wassermann reaction when the serum gives a negative one. 



In congenital syphilis a large proportion of the cases 

 yield a positive reaction. Adequate treatment of the 

 syphilis leads to a condition in which the Wassermann 

 reaction, previously positive, becomes negative. In such 

 a case the reaction usually becomes weaker and weaker, 

 and finally two or three months after the commencement 

 of treatment it becomes entirely negative. The reaction 

 is valuable for estimating the efficiency of treatment ; if 

 the treatment is successful the reaction remains perma- 

 nently negative, but an interval of six months should be 

 allowed to elapse after the cessation of the course of treat- 

 ment before a negative reaction should be accepted as 

 proof that the syphilitic virus has been destroyed, and 

 a further test after a lapse of twelve months is desirable. 

 Some American authors assert that chronic alcoholism 

 induces a condition in which the syphilitic individual does 

 not give a positive Wassermann reaction. The Wasser- 

 mann reaction is frequently absent during pregnancy and 

 is negative in Vincent infections (Taylor and McKinstrey). 



The details for carrying out the Wassermann reaction 

 are given at p. 614. 



M.B. 39 



