APPLICATION OF COMPLEMENT FIXATION 201 



cases which have been examined shortly after death, has shown the 

 presence of the treponema in lesions which previously had not been 

 positively known to be syphilitic. Symmers, Darlington and Bittman 

 found a considerable divergence between ante-mortem Wassermann 

 tests and the post-mortem evidence of syphilis, but Turnbull finds a 

 striking agreement. Certainly syphilis can progress for a long time 

 without gross morbid anatomical manifestations, and it seems possible 

 that the pathologist cannot be sure of excluding syphilis in his ana- 

 tomical diagnosis. Improved technic is the only way of reducing this 

 factor of error and thereby providing an accurate control of the Was- 

 sermann and other clinical tests. 



The Diagnostic Value of the Wassermann Test. Naturally this 

 subject has been studied extensively and figures vary as the technic is 

 improved. In 1914 Boas published an analysis of over 8000 cases 

 reported in the older literature and tabulates them as follows : 



Number Positive Per - c ^ nt> 

 of cases positive 



Primary syphilis 1060 629 59 



Secondary syphilis 3526 3181 90 



Tertiary syphilis 1212 1020 84.1 



Early latent syphilis 983 504 51 



Late latent syphilis 1520 605 39 



Tabes dorsalis 159 115 72 



Paresis 405 402 99.2 



These figures are sufficient to indicate that the Wassermann test is 

 of distinct value in the diagnosis of syphilis. More recent statistics 

 offered by Craig as the result of tests carried out by himself illustrate 

 the accuracy of the reaction as applied under excellent conditions. 

 In interpreting the following figures from Craig, given as the result 

 of a single test on each of 4658 cases diagnosed as syphilis, it must 

 be remembered that there is at least a small factor of error in the 

 clinical diagnosis. The table follows: 



Number p os itive Percent, 

 of cases positive 



Primary syphilis 908 813 89.5 



Secondary syphilis 1889 1817 96.1 



Tertiary syphilis 638 558 87.4 



Latent syphilis 1 173 790 67.3 



Congenital syphilis 28 25 89.2 



Parasyphilis 22 7 68.1 



4658 4010 86.2 



Tests made by Craig on 2643 individuals, either not diseased or vic- 

 tims of disease other than syphilis, showed the reaction to be positive in 

 eleven instances (0.4 per cent.). These eleven instances included four 

 cases of malaria, three of tuberculosis (two of which ultimately gave a 

 clinical history of syphilis), three cases of pityriasis rosea and one case 

 in which the diagnosis was not established. It is to be considered pos- 

 sible that diseases other than syphilis may produce those changes in the 

 blood which lead to fixation of syphilitic antigen and complement; 

 among these are occasional cases of leprosy, scarlatina, malaria, try- 



