486 THE TECHNIC OF COMPLEMENT-FIXATION REACTIONS 



reactions occurring in ten days or more after the chancre made its ap- 

 pearance. 



(6) In general, in primary syphilis the Wassermann reaction will be 

 positive in about 80 to 90 per cent, of cases; where cholesterinized ex- 

 tracts are used as antigens, or with the Noguchi system, using active 

 serum, the reactions are secured earlier and in a larger percentage of 

 cases. Craig 1 has reported 34 per cent, positive reactions during the 

 first week after the appearance of the chancre; 57 per cent, during the 

 second week; 67 per cent, during the third week; 76 per cent, during the 

 fourth week, and 80 per cent, during the fifth week. 



(c) It is generally agreed that a diagnosis should be made as early as 

 possible, and vigorous treatment instituted. A Wassermann reaction 

 may be performed, and if it shows a positive result, this indicates the 

 presence of syphilis, even if the lesion under suspicion is not specific, the 

 reaction being due to a previous infection. A negative reaction, how- 

 ever, does not exclude syphilis, and if it is at all possible, a microscopic 

 examination, using the dark-ground illuminator, should be made for 

 the treponema. In primary syphilis a microscopic examination of the 

 secretions of the lesion by a competent person is usually more valuable 

 than the serum test; as a general rule, both examinations should be 

 made, especially with patients in whom the chancre is almost healed or 

 atypical. 



(d) The cerebrospinal fluid of persons in the primary stage of syphilis 

 has always reacted negatively (Boas). 



2. In Secondary Syphilis. It is in untreated cases of secondary 

 syphilis that the remarkable specificity of the Wassermann reaction 

 is so well demonstrated. The initial lesion may have been inconspicuous 

 and hence have been overlooked, and the secondary lesions may be 

 quite mild and inconclusive; in either case the Wassermann reaction 

 will usually establish the diagnosis. 



(a) In untreated secondary syphilis the reaction is positive in from 

 92 to 100 per cent, of cases. In the examination of 437 serums from 

 untreated cases Boas has never had a negative reaction, and my own 

 experience has been the same. Craig reports 96 per cent, positive re- 

 actions. 



(6) With the serums of patients who have received some treatment 

 the percentage of positive reactions will be slightly lower. Of 310 such 

 cases examined by Boas, 97.6 reacted positively. The influence of 

 treatment upon the reaction is to be remembered, and a single negative 

 reaction does not by any means exclude the possibility of syphilis. 

 1 Amer. Jour. Med. Sci., 1915, cxlix, 41. 



